Stock Market Terms: The A-Z AI Trading Glossary

Trading that happens after the 4 p.m. ET close through electronic networks instead of the main exchange. Volume is thin and spreads are wide, so prices swing hard on small orders, which is why after-hours news reactions look bigger than they really are.

The lowest price a seller will currently accept for a stock. Pair it with the bid, and the gap between them tells you how liquid and how expensive a stock really is to trade.

A prolonged drop of 20% or more from recent highs, usually paired with pessimism and falling volume. Bear markets feel permanent while you're in one and look obvious only in hindsight, which is exactly why most people sell at the bottom.

The highest price a buyer will currently pay for a stock. It's one half of every quote and what you'd get filling a market sell order right now.

The gap between the highest bid and the lowest ask. A penny spread means deep liquidity; a wide spread is a hidden tax you pay every time you enter and exit.

A large, established company with a long record of stable earnings and often a dividend. They won't double overnight, but they're the ballast most portfolios are built around.

A loan you make to a company or government that pays you interest and returns your principal at maturity. Bonds are the steady, boring counterweight to stocks, which is exactly why most balanced portfolios hold them.

What a company would be worth on paper if it sold every asset and paid off every debt. Value investors compare it to the share price to spot stocks trading below their breakup worth.

A sustained rise in prices, usually a 20% gain off the lows, fueled by optimism and rising participation. The hard part isn't spotting one, it's not getting reckless once everyone agrees it's happening.

Buying quality assets and holding for years instead of trading in and out. It's unglamorous and it quietly beats most active traders over a full market cycle.

Buying back shares you sold short to close the trade and return the borrowed stock. It's the exit half of every short, and in a squeeze it's where the panic buying comes from.

The profit you make when you sell an asset for more than you paid. Hold longer than a year and it's usually taxed lighter than your paycheck, a quiet edge most beginners ignore.

The loss you take when you sell an asset for less than you paid. It stings, but it can offset gains at tax time, so a losing trade isn't always a total write-off.

An automatic, market-wide trading halt that triggers when an index falls a set percentage in a day, meant to stop panic from feeding on itself. It's a cooling-off switch, not a fix, and the selling often resumes when trading reopens.

The standard share most investors buy, giving partial ownership, voting rights, and a claim on profits after everyone else is paid. It carries the most upside and the most risk, since common holders are last in line if the company fails.

Earning returns on your past returns, so growth snowballs instead of crawling. Give it enough time and it does more heavy lifting than any single stock pick, which is why starting early beats investing more later.

A drop of about 10% or more from a recent high, milder than a bear market. Corrections are routine and often healthy, shaking out the froth before the next leg up.

A company whose fortunes rise and fall with the economy, like airlines, automakers, and hotels. They run hot in good times and get hit hardest in a slowdown, so the cycle matters more than usual.

An order to buy or sell that expires at the end of the trading day if it isn't filled. It's the default on most platforms, which means orders you set and forget quietly vanish at the close unless you mark them good-til-canceled.

Someone who opens and closes positions inside the same session and holds nothing overnight. It's the fastest game in the market, and the PDT rule plus thin margins wash most beginners out early.

A company that holds up when the economy weakens, like utilities, healthcare, and consumer staples. People pay the power bill in any market, which is what makes these names steadier in a downturn.

A slice of company profits paid to shareholders, usually quarterly, in cash or extra shares. Dividends reward patience, but a yield that looks too good often signals a falling stock price, not generosity.

A stock chosen mainly for steady dividend payments rather than fast price growth. They're popular for income and lower volatility, but chasing the highest yield on the screen is how beginners walk into value traps.

A stock's annual dividend divided by its share price, shown as a percentage. A yield that looks unusually high is often a warning, since it usually means the price fell, not that the payout got generous.

A price-weighted index of 30 large, established U.S. companies, quoted as 'the Dow.' It's old and narrow, so it's more a sentiment headline than a true read on the whole market.

Your ownership stake in a company, or the value of what you actually own in an account after debts. Equities is also just the grown-up word for stocks.

An order that must be filled completely and immediately or it's canceled outright, with no partial fills. Big traders use it when they need the entire position at once or none at all.

The number of shares actually available for public trading, after locked-up insider and institutional shares are removed. A low float means small orders move price violently, which is great for momentum traders and brutal for everyone caught on the wrong side.

Valuing a stock by studying the actual business: revenue, earnings, debt, and growth. It answers what a company is worth, while technical analysis only tracks what the price is doing.

An order that stays open until it fills or you cancel it, instead of expiring at the close. It's the set-and-forget way to wait for your price without watching the screen all day.

A company expected to grow earnings faster than the market, usually reinvesting profits instead of paying dividends. You pay up front for future growth, and when that growth slows, the fall is fast.

A basket of stocks used to measure a slice of the market, like the S&P 500 or Nasdaq 100. You can't buy an index directly, but you can buy a fund that tracks it.

What a stock is actually worth based on its fundamentals, separate from its market price. When intrinsic value sits well above the price, you've found what value investors hunt for.

An Initial Public Offering, the first time a private company sells shares to the public. The hype is loudest on day one, which is usually the worst time to buy, since many IPOs trade below their debut price within a year.

A company worth roughly $10 billion or more in total market value. They move slower than small caps but survive downturns that wipe out smaller names.

Using borrowed money to control a bigger position than your cash allows. It multiplies wins and losses alike, and overusing it is the single fastest way to blow up an account.

An order to buy or sell only at a specific price or better. It protects you from bad fills, but it can also leave you watching a stock run without you because your price never hit.

How easily you can buy or sell a stock without moving its price. High liquidity means tight spreads and clean fills; low liquidity is where good trades go to die on the exit.

Borrowed money from your broker used to buy more stock than your cash allows. It magnifies gains and losses equally, and the margin call always comes at the worst possible moment.

When prices detach from reality and run on hype, speculation, and the fear of missing out. Bubbles look obvious only after they pop, which is why 'this time is different' is the most expensive phrase in markets.

A company's total value, found by multiplying share price by shares outstanding. It's how the market sorts companies into small, mid, and large cap, and a better size gauge than share price alone.

A sudden, steep, fast drop across the whole market, usually driven by panic or a shock. Crashes erase years of gains in days, but forced selling is also where the next decade's bargains get made.

An order to buy or sell immediately at the best available price. It guarantees you get filled, not the price you wanted, which is dangerous on thin, fast-moving stocks.

Buying what's already rising and riding the trend until it breaks. It works because strength attracts strength, right up until the crowd turns and the exit gets crowded.

An index of more than 3,000 Nasdaq-listed stocks, heavily tilted toward tech. When people gauge how tech is doing, this is the number they're watching.

What a company keeps after every expense, tax, and interest payment, the real bottom line. Revenue grabs the headline, but net income is what actually pays shareholders.

The share of revenue left as profit from core operations, before taxes and interest. A fat, stable operating margin is a quiet sign the business runs efficiently.

A stock trading under about $5 a share, usually for a small, unproven company. The lottery-ticket upside gets the headlines; the reality is wide spreads, thin volume, and a graveyard of pump-and-dumps.

The full collection of investments you hold, from stocks and ETFs to bonds and cash. How you build and balance it matters far more to your returns than any single pick.

A trader who holds for weeks to months, riding bigger trends and ignoring the daily chop. It's the patient middle ground between day trading and buy-and-hold investing.

Trading before the 9:30 a.m. ET open, typically from 4 a.m. on electronic networks. It's where overnight news gets priced in, but thin volume makes the moves unreliable until the regular session confirms them.

A share class that pays fixed dividends and gets paid before common stock in a liquidation, but usually carries no voting rights. It behaves more like a bond than a stock: steadier income, less upside.

A business whose shares aren't sold on a public exchange, owned by founders, employees, or private investors. Think SpaceX or IKEA: you can't buy in through your brokerage.

The percentage of revenue a company keeps as profit after all expenses. A 20% margin means 20 cents of every sales dollar sticks, and rising margins often signal real pricing power.

A business that has sold shares to the public and trades on an exchange, with strict reporting rules. That transparency is exactly what lets you research it before you buy.

The total money a company brings in from sales before any costs come out, the top line. It shows demand for the product, but revenue without profit is just expensive activity.

An index tracking 2,000 small-cap U.S. companies, the go-to gauge for the small end of the market. Traders watch it for a read on domestic growth and risk appetite.

An index of 500 of the largest U.S. companies, the standard benchmark for the overall market. When someone says 'the market returned 10%,' this is almost always what they mean.

A single unit of ownership in a company. Own one and you own a sliver of the business, its profits, and its risk.

Borrowing shares to sell now and buy back later, betting the price falls. Gains are capped at 100% but losses are unlimited, since a stock can keep rising forever, and short squeezes are how accounts blow up.

A company worth roughly $300 million to $2 billion. Bigger growth potential, bigger swings, and far more likely to get knocked around by a single bad quarter.

A stock priced on a big future bet rather than today's results, like an early biotech or pre-revenue tech name. The upside can be huge, but so is the odds it goes to zero, so size it like a lottery ticket.

The marketplace where stocks are bought and sold, like the NYSE or Nasdaq. It's the plumbing that matches buyers with sellers and keeps prices public and continuous.

A two-part order that becomes a limit order once your stop price is hit. It protects you from terrible fills, but in a fast crash price can blow past your limit and leave you unfilled, still holding the loss.

A standing order to sell once a stock drops to a set price, designed to cap your loss. It only works if you actually set it, since most blown-up accounts had a stop in mind and never placed it.

A trader who holds positions for days to a couple of weeks, aiming to catch the meat of a move. It demands less screen time than day trading while still leaning on charts and timing.

The short letter code that identifies a stock, like AAPL for Apple. It's the stock's name tag across every platform and quote feed.

A stop-loss that follows the price up as a trade works, locking in gains while leaving room to run. It automates the hardest part of trading, the exit, instead of leaving it to your nerves.

A stock that looks cheap relative to earnings, assets, or cash flow, often overlooked or out of favor. The trick is telling a genuine bargain from a company that's cheap because it's dying.

A real-time gauge of expected S&P 500 volatility, nicknamed the fear index. It spikes when investors panic and sits low when they're calm, so extreme readings often mark turning points.

How much and how fast a price moves, up or down. More volatility means more opportunity and more risk; it's the raw material traders work with and the thing that scares investors out at the bottom.

The number of shares traded over a period. Volume is the conviction behind a move: a breakout on heavy volume means something, the same move on light volume usually doesn't.

The highest price a stock has traded over the past year. Stocks near their 52-week high often have momentum, but it's a level where profit-taking shows up too.

The lowest price over the trailing year. Bargain hunters watch it and so do short sellers, since a fresh 52-week low rarely happens for no reason.

Short for all-time high, the highest price a stock has ever traded. It sounds bullish, but buying purely because something is at an ATH with no setup is chasing, not investing.

All-time low, the lowest price in a stock's history. A new low can mean a bargain or a falling knife, and the chart alone won't tell you which.

The total dollar value a fund or advisor manages for clients. It's the headline size metric for funds and robo-advisors, though bigger doesn't automatically mean better returns.

The smoothed yearly growth rate of an investment over time, as if it grew at a steady pace. It's the honest way to compare returns, since it strips out the noise of a single lucky year.

A company's total debt divided by shareholder equity, showing how much it runs on borrowed money. A high ratio can mean aggressive growth or a fragile balance sheet, depending on the business.

Investing a fixed amount on a set schedule regardless of price. It removes the impossible job of timing the market and quietly beats most people who try to.

The research you do before risking money: earnings, debt, management, the actual business. Do your own DD is trader shorthand for don't buy because a stranger online told you to.

Earnings before interest, taxes, depreciation, and amortization, a rough proxy for operating profit. It's useful for comparing companies, but executives love it because it can hide real costs.

The market close, used for orders, data, and reports settled at day's end. End-of-day signals are calmer and less noisy than intraday ones.

A company's profit divided by its shares outstanding. It's the number Wall Street fixates on every quarter, and beating or missing it by a penny can swing a stock double digits.

The urge to chase a stock that's already running because everyone else seems to be winning. FOMO buys the top; it's the single most expensive emotion in trading.

The highest price a stock reaches during the session. Day traders watch it as a momentum and breakout marker.

The lowest price of the session. A break below the LOD often triggers stops and fresh selling.

Shorthand for moving average, a line that smooths price over a set number of periods. Traders use the 50-day and 200-day as quick trend gauges.

The per-share value of a fund's holdings, calculated daily. For ETFs, a price trading far from NAV is a flag worth checking.

The four prices that define a single bar or candle: where it opened, its high, its low, and where it closed. It's the raw data every chart is built from.

A stock's price divided by its earnings per share, showing how much you pay for each dollar of profit. A high P/E means high expectations and a long way to fall if the company disappoints.

Your profit and loss, what you're up or down on a position or over a period. Watching your P&L instead of your plan is how good setups turn into emotional exits.

The P/E ratio divided by the earnings growth rate, meant to judge whether a high valuation is justified by growth. A PEG near 1 is the rough line between paying up fairly and overpaying.

An analyst's or trader's projected future price for a stock. Treat it as an opinion with a number attached, not a promise, since targets get revised constantly.

How much profit a company squeezes from its assets, as a percentage. It shows how efficiently the business actually uses what it owns.

Profit measured against shareholder equity, how well a company turns your money into more money. Consistently high ROE is a quiet sign of a quality business.

Your gain or loss on an investment as a percentage of what you put in. Simple to calculate and easy to fudge, since it means nothing without the time period attached.

Short for time and sales, the live, scrolling record of every executed trade with price, size, and timestamp. Reading the tape this way is how day traders gauge real buying and selling pressure.

Performance measured from January 1 to today. It's the standard yardstick for comparing how a stock or portfolio is doing this year.

A measure of how much a stock typically moves in a day, in dollars. Traders size positions and set stops around ATR so a normal wiggle doesn't shake them out.

Three lines that wrap around price using a moving average and standard deviation, expanding and contracting with volatility. Price riding the upper band isn't an automatic sell; in a strong trend it can hug that band for weeks.

When price falls below a clear support level on rising volume. It's the bearish mirror of a breakout, and it often triggers a cascade of stop-loss orders.

When price pushes above a defined resistance level, ideally on heavy volume. The clean ones run; the fakeouts trap everyone who bought the first green candle.

A stretch where price moves sideways in a tight range, with buyers and sellers in a standoff. Tight consolidation often precedes a sharp move: the longer the coil, the bigger the snap.

When the 50-day moving average crosses below the 200-day, a widely watched bearish signal. It's more confirmation than prediction; by the time it prints, much of the damage is done.

When price and an indicator like RSI move in opposite directions, hinting the trend is weakening. It's an early warning, not a trigger, and can persist far longer than your account can wait.

A moving average that weights recent prices more heavily, so it reacts faster than a simple average. Short-term traders lean on the 9 and 21 EMA to track momentum.

Horizontal levels (38.2%, 50%, 61.8%) used to estimate where a pullback might pause before the trend resumes. They work partly because so many traders watch the same lines and act on them.

When the 50-day moving average crosses above the 200-day, a classic bullish signal. Like its death-cross opposite, it confirms a trend already underway rather than calling the bottom.

Moving Average Convergence Divergence, a momentum indicator built from two moving averages and a signal line. Crossovers flag shifts in momentum, but in choppy markets it whipsaws traders to death.

A line that averages price over a set number of periods to smooth out noise and reveal the trend. The 50-day and 200-day are the two most-watched lines on Wall Street.

A condition where a stock has risen far and fast, often flagged by RSI above 70. Overbought doesn't mean sell; strong stocks stay overbought while weak traders short them too early.

A stock that's fallen hard and fast, often shown by RSI under 30. It signals a possible bounce, not a guaranteed one, since oversold can always get more oversold.

A short, shallow dip against the prevailing trend. Buying pullbacks in an uptrend is one of the oldest edges there is; the discipline is waiting for it instead of chasing.

How today's volume compares to a stock's average, expressed as a multiple. High RVOL is the day trader's green light: something is actually happening, not just drifting.

A price level where selling tends to appear and stall a rally. The more times price tests resistance, the more meaningful the eventual break or rejection becomes.

A momentum gauge scored 0 to 100 that flags when a stock looks overbought (above 70) or oversold (below 30). A high RSI doesn't mean sell; it means the move is stretched and due for a rest, which is exactly where beginners get burned chasing.

A moving average that weights every period equally over the chosen window. Slower to react than the EMA, which makes it better for spotting the bigger trend and worse for fast entries.

A momentum indicator comparing a stock's close to its recent range, scored 0 to 100. It's tuned for range-bound markets and gives false signals when a strong trend runs.

A price level where buyers tend to step in and stop a stock from falling further. Traders watch it because a clean bounce can mark an entry, while a decisive break below often signals the trend is turning.

Reading price, volume, and chart patterns to judge where a stock might go next, instead of studying the business. It won't tell you what a company is worth, but it's how traders time entries and exits.

The general direction price is moving over time: up, down, or sideways. The trend is your friend survives as a cliche because fighting a strong trend is the fastest way to lose money.

A straight line drawn along a series of highs or lows to map a trend's direction and slope. A clean break of a long-respected trendline is often the first real sign the move is over.

A chart overlay showing how much volume traded at each price level rather than over time. The high-volume zones act as magnets and battle lines, where price tends to stall or react.

Volume-Weighted Average Price, the average price weighted by volume across the day. Institutions use it as a fair-value benchmark, and day traders treat it as intraday support or resistance.

A two-candle pattern where a big red candle completely swallows the prior green one, signaling sellers took control. It carries the most weight at the top of an extended run.

A green candle that fully engulfs the prior red one, showing buyers overwhelmed sellers. It's strongest after a clear downtrend and on heavy volume.

A small candle that sits inside the body of the previous larger red candle, hinting selling momentum is stalling. It signals indecision, not a confirmed reversal, so wait for the next candle.

A chart bar showing the open, high, low, and close for a period in a single shape. Its body and wicks reveal the fight between buyers and sellers at a glance, which is why it beats a plain line chart.

A bullish pattern shaped like a rounded bottom (the cup) followed by a small pullback (the handle) before a breakout. It signals a base building strength, and the breakout from the handle is the classic entry.

A candle where the open and close finish at nearly the same price, leaving a thin or nonexistent body. It signals indecision, with buyers and sellers fought to a draw, and matters most after a strong run.

A W shape where price tests a low twice and bounces, signaling support held and buyers are stepping in. The pattern confirms only when price breaks above the middle peak.

An M shape where price fails twice at the same high, a warning that buyers are exhausted. It confirms when price breaks below the valley between the two peaks.

A three-candle bearish reversal: a strong up candle, a small indecisive one, then a strong down candle. It marks a likely top after an uptrend.

A short, tight consolidation that slopes against the prior sharp move, like a flag on a pole. It usually resolves in the direction of the original trend: a pause, not a reversal.

A jump between one candle's close and the next one's open, leaving an empty space on the chart. Gaps often fill as price returns to the level later, which traders fade or follow depending on the catalyst.

A candle with a small body and a long lower wick, showing buyers rejected lower prices. After a downtrend, it hints the selling may be exhausted.

Looks like a hammer but appears at the top of an uptrend, warning that sellers are testing the waters. It needs a red candle after it to confirm the turn.

A three-peak reversal pattern with a higher middle peak (the head) flanked by two lower ones. A break below the neckline is one of the more reliable signals that an uptrend is done.

A small body with a long upper wick after a downtrend, hinting buyers tried to push price up. Like the hammer, it needs confirmation before you trust it.

A candle with a full body and almost no wicks, meaning one side dominated from open to close. It signals strong conviction in that direction.

A three-candle bullish reversal: a strong down candle, a small pause, then a strong up candle. It often marks a bottom after a decline.

A small symmetrical triangle that forms after a sharp move as price coils. Like a flag, it typically breaks in the direction of the original trend.

A candle with a small body and long upper wick at the top of a rally, showing buyers lost a fight they started. It's a common early sign of a reversal.

A small-bodied candle with wicks on both sides, reflecting indecision. One alone means little; clusters of them mark a market catching its breath.

Three long red candles in a row, each opening within the prior body and closing lower, signaling steady selling pressure. It's a strong bearish reversal after an uptrend.

Three long green candles in a row, each closing higher, showing buyers in firm control. It's a bullish reversal signal after a downtrend, best on solid volume.

A pattern where price coils between converging trendlines until it breaks out. Ascending triangles lean bullish, descending lean bearish, and the breakout direction is the trade.

A pattern where two trendlines slope the same way and converge, signaling a weakening trend. A rising wedge often breaks down; a falling wedge often breaks up.

An AI system that plans and takes multi-step actions on its own, researching, analyzing, even placing trades, instead of just answering a prompt. Agentic trading is the 2026 buzzword; the catch is that an agent acting unsupervised can compound a bad assumption fast.

Using pre-set computer rules to place trades automatically based on price, timing, or other signals. It's deterministic: the same input always fires the same trade, which is both its strength and its blind spot.

Non-traditional data used to gauge a company: satellite images of parking lots, credit-card spend, app downloads, web traffic. Hedge funds pay fortunes for it, and the retail reality is that it's usually priced in by the time you hear about it.

AI techniques that flag data points or trades that break from the normal pattern. In markets it surfaces unusual volume, price spikes, or potential manipulation worth a second look.

A connection that lets software talk to software, how a trading bot pulls live prices or sends orders to your broker. If a tool offers API access, it means you can automate it instead of clicking by hand.

Software that places trades for you based on rules or AI signals, with no human clicking the button. The honest truth: most retail bots underperform a simple plan, because markets shift faster than fixed logic adapts.

Running a strategy against historical price data to see how it would have performed before you risk real money. The trap: a strategy that looks flawless on past data can still fail live, because markets don't repeat themselves cleanly, which is why walk-forward testing exists.

An AI model whose decisions can't be easily explained, even by its builders. In trading that's a real risk: if you can't see why it bought, you can't tell when it's broken.

A branch of machine learning using layered neural networks to find complex patterns in huge datasets. It powers the heaviest AI trading models, but it needs enormous data and can latch onto noise that looks like signal.

AI built so humans can understand why it made a given decision. Regulators are pushing hard for it in finance, with the EU's AI Act, fully in force in 2026, treating opaque trading models as high-risk.

AI that creates new content, text, summaries, code, from what it learned, like the model writing this. Traders use it to digest earnings calls and news in seconds, but it can state wrong facts with total confidence.

Ultra-fast automated trading that fires thousands of orders in fractions of a second to exploit tiny price gaps. It's an institutional arms race retail can't win; the edge is being nowhere near it.

An AI trained on massive text to understand and generate language, the engine behind tools like ChatGPT and Claude. In trading it shines at summarizing news and sentiment, not at predicting prices, and anyone selling the latter is overselling.

A type of AI that learns patterns from data and improves with more of it, instead of following fixed rules. It's probabilistic: feed it the same setup twice and it may act differently as it updates.

A method that runs thousands of randomized scenarios to map the range of possible outcomes for a strategy or portfolio. It won't predict the future, but it shows you how bad a realistic bad day could get.

AI that reads and interprets human language: news, filings, social posts, earnings calls. It's the engine under most sentiment tools, turning a wall of text into a tradeable score.

A model loosely inspired by the brain, with layers of connected nodes that learn patterns from data. It's the workhorse behind modern AI trading systems and also the hardest to interpret.

When a model learns the noise in past data so well it nails history and fails in the real world. It's the number-one reason backtested strategies fall apart live, and the easiest trap to fool yourself with.

Practicing with fake money in real market conditions to test a strategy or platform. It builds skill without risk, but it can't replicate the one thing that breaks traders: your emotions with real money on the line.

AI's ability to spot recurring chart, volume, or price shapes faster than a human can scan. Useful for surfacing setups, as long as you remember a recognized pattern is a probability, not a promise.

Using historical data and statistics to estimate the odds of future outcomes. In trading it powers forecasts and signals, but probability is the key word, not certainty.

Trading and investing decisions driven by math, statistics, and data rather than gut or narrative. The quants who run it dominate modern markets, which is why data discipline beats hot takes.

A machine-learning approach where a model learns by trial and error, rewarded for good outcomes in simulated markets. It's powerful and fragile: a model that aces the simulation can still misread a market it's never seen.

Scoring the mood of news, social media, or filings as bullish, bearish, or neutral. It can flag a shift before price reacts, but crowds are often loudest right before they're wrong.

A single number summarizing whether the chatter around a stock leans positive or negative. Treat it as one input among many, since sentiment is a coincident signal as often as a leading one.

Technology that automatically splits and routes an order across exchanges for the best price and fastest fill. It's standard plumbing on modern platforms, working quietly behind every click.

A tool that filters thousands of stocks in real time to surface ones meeting your criteria: volume spikes, breakouts, news. It turns an impossible amount of data into a short, tradeable watchlist.

A filter that narrows the market by metrics like price, market cap, P/E, or sector. Scanners hunt live action; screeners build longer-term shortlists from fundamentals.

A specific cue to buy or sell, generated by an indicator, algorithm, or AI model. A signal is a suggestion with a track record, not an order: the good ones tell you their win rate, the bad ones just sound confident.

The historical information an AI model learns from before it's used. Garbage in, garbage out: a model is only as good as the data it studied, and stale or biased data quietly poisons the output.

Testing a strategy on one slice of history, then walking it forward onto unseen data to check it still holds up. It's the tougher, more honest cousin of a basic backtest.

An option whose strike price sits right at the current stock price. ATM options carry the most time value and the most sensitivity to a move.

When futures contracts for later dates trade cheaper than nearer ones, often signaling tight current supply. It's the opposite of contango and shapes the returns of commodity and volatility ETFs.

A contract giving you the right to buy a stock at a set price before a deadline. You buy calls when you expect a stock to rise, but time decay works against you the whole way.

Selling a put option while holding enough cash to buy the shares if assigned. It's a way to get paid to wait for a stock at a price you'd actually want to own it.

When later-dated futures cost more than nearer ones, common in normal markets. For ETFs that roll contracts, contango quietly bleeds returns over time, the reason many leveraged commodity funds decay.

Selling a call option against shares you already own to collect income. You pocket the premium but cap your upside: fine in a flat market, frustrating in a rally.

A fund that holds stocks and sells call options against them to generate income, paid out as high monthly distributions. The tradeoff is capped upside: in a fast rally these funds lag the index, which is the part the yield headlines leave out (think JEPI and JEPQ).

An options strategy where you sell one option and buy a cheaper one to collect net premium upfront. It caps both your gain and your loss, a defined-risk way to bet on direction or time decay.

Buying one option and selling another against it to cut the cost of a directional bet. You give up some upside in exchange for a cheaper, lower-risk entry.

How much an option's price moves for a $1 move in the stock, and a rough proxy for the odds it finishes in the money. A delta of 0.50 means the option moves about 50 cents per dollar.

How many days are left until an option expires. Fewer days means faster time decay, and short-DTE options move violently and die quickly.

A basket of stocks, bonds, or commodities you can buy and sell like a single stock all day long. It hands you instant diversification, usually at a lower fee than a mutual fund.

The yearly fee a fund charges, taken as a percentage of your investment. It sounds tiny, but a 1% ratio versus 0.05% compounds into a massive gap over decades.

The day an options contract expires and either settles or becomes worthless. As it nears, time value evaporates fastest, and the clock is the option seller's best friend.

An agreement to buy or sell an asset at a set price on a future date, traded with heavy leverage. Futures move fast and trade nearly around the clock: powerful and unforgiving for the undercapitalized.

How fast an option's delta changes as the stock moves. High gamma near expiration is why short-dated options can swing from worthless to printing in minutes.

A lightly regulated private fund that uses aggressive tactics like leverage, shorting, and derivatives chasing high returns. They're walled off for wealthy investors, and plenty still trail a plain index fund.

The market's forecast of how much a stock will move, baked into option prices. High IV means expensive options and a big expected move: buy options when IV is low, not after it's spiked.

A fund that tracks a market index like the S&P 500 instead of trying to beat it. Low cost and boring on purpose, it quietly outperforms most active managers over time.

A fund built to move opposite its index, used to bet on or hedge a decline. Daily rebalancing makes it decay if held too long, so it's a short-term tool, not a buy-and-hold.

An options strategy combining a call spread and a put spread to profit when a stock stays in a range. Defined risk, defined reward, and a favorite for traders betting on boredom.

An option with real intrinsic value: a call below the stock price or a put above it. ITM options cost more but behave more like the stock itself.

Long-dated options that expire a year or more out. They give you stock-like exposure for less capital, with far more time before decay becomes the enemy.

A fund using debt and derivatives to amplify an index's daily return, often 2x or 3x. The daily reset means it decays in choppy markets: a trading vehicle, not an investment.

A professionally managed pool of investor money spread across many holdings, priced once a day after the close. It offers diversification, but active management and higher fees often drag returns below a simple index.

The total number of option contracts still open and not yet closed. Rising open interest with rising volume shows new money and conviction flowing into a strike.

An option with no intrinsic value yet: a call above the stock price or a put below it. They're cheap lottery tickets with big percentage payoffs, low odds, and fast decay.

The price you pay to buy an option, or collect to sell one. For buyers it's the most you can lose; for sellers it's the income, with far bigger risk attached.

A contract giving you the right to sell a stock at a set price before a deadline. You buy puts to profit from a fall or to insure shares you own.

A company that owns income-producing real estate and trades like a stock, passing most profits to shareholders as dividends. It's how you collect rent checks without ever buying a building.

A fund holding stocks from one slice of the economy: tech, energy, healthcare. It's how you bet on a theme without picking the single winner.

The fixed price at which an option can be exercised. It's the line in the sand, where the contract starts to pay, and the anchor for every option strategy.

How much value an option loses each day from time decay, all else equal. Theta is the option buyer's quiet enemy and the seller's steady paycheck.

How much an option's price moves when implied volatility changes by one point. High vega means your trade lives or dies on volatility, not just direction.

A large, privately negotiated order, often broken up to avoid moving the market. Spotting block trades in options flow is how traders track where big institutional money is positioning.

The platform or firm that executes your buy and sell orders, like Fidelity, Schwab, or Robinhood. 'Free' trading isn't charity, since brokers still earn from routing your orders and lending your idle cash.

Software for viewing price charts with indicators, drawing tools, and scanners. It's the cockpit most traders live in, with TradingView and TrendSpider among the common names.

The fee a broker charges to place a trade. Most U.S. brokers dropped per-trade commissions years ago, but the cost didn't vanish, it just moved into the spread and order routing.

Buying and selling stocks with no per-trade fee, now standard at most U.S. brokers. It's not charity: brokers make money routing your order, so free has a quiet cost in your fill price.

A private exchange where large orders trade away from public view to avoid moving the price. Dark-pool prints reveal big institutional activity after the fact, which is why flow tools track them.

A setup that sends your orders straight to the exchange instead of through a broker's routing. Active day traders pay for it to get faster fills and control over where orders go.

A color-coded visual showing which stocks or sectors are up or down at a glance. It's a fast way to read where money is rotating across the market.

Keyboard shortcuts that fire orders instantly without clicking through menus. For fast day trading, hotkeys are the difference between catching a move and watching it.

A live view of the order book showing bids and asks beyond the best price, with size at each level. It exposes supply and demand in real time, though spoofed orders can make it lie.

A brokerage account that lets you trade with borrowed money and short stocks. It unlocks leverage and the pattern day trader rules, plus the ability to lose more than you put in.

A firm that quotes both a buy and sell price to keep a stock tradeable, profiting from the spread. They provide liquidity, and in options they hedge constantly, activity sharp traders try to read.

The real-time stream of large and unusual options trades, used to track where big money is betting. Flow tools filter the noise to surface size and urgency, but the trades still need context before you follow them.

The actual process of your order getting filled at a price. Good execution means tight, fast fills; poor execution leaks money through slippage on every trade.

A simulated account that trades real market data with fake money. It's the safest place to test a broker, a strategy, or your own discipline before funding.

A rule that limits accounts under $25,000 to three day trades in any rolling five-day window. It's the biggest reason small accounts feel boxed in, and it's why the $25K threshold keeps coming up in trading circles.

The volume of put options divided by call options, used as a sentiment gauge. Extreme readings often work as contrarian signals, since peak fear and peak greed both show up here first.

Live market prices with no delay, versus the 15-minute lag on many free feeds. If you're making intraday decisions on delayed data, you're trading the past.

The path your order takes to get filled, across exchanges or market makers. Where an order routes affects your speed and price more than most retail traders realize.

The percentage of a stock's float currently sold short. High short interest sets the stage for a short squeeze if the stock climbs and shorts scramble to cover.

The gap between the price you expected and the price you got. It widens on fast or thin stocks and quietly eats returns, the hidden cost of chasing.

Shorthand for institutional and professional traders presumed to have better information or tools. Following smart money through flow data is popular, but they're wrong plenty too, and they can absorb losses you can't.

An aggressive order split across multiple exchanges to fill immediately, prioritizing speed over price. In options flow, sweeps often signal urgency: someone wants in now, before a move.

The live, scrolling list of every executed trade with price, size, and time. Reading the tape is how day traders feel real-time buying and selling pressure.

A temporary pause in a stock's trading, triggered by news, volatility, or an exchange. Halts protect against chaos, but the reopen can gap hard in either direction.

A surge in an option's volume far above its normal average, often a sign institutions are positioning for a move. It's a clue, not a crystal ball, since one big trade can be a hedge, not a directional bet.

A curated list of stocks you're tracking for setups. A tight, well-built watchlist is the quiet backbone of a consistent process, the opposite of staring at the whole market.

The return a trade or strategy earns above its benchmark, the actual skill, not just riding the market up. It's where FullStack Alpha gets its name: the goal is the excess return, not the noise.

Freezing up because you have too many indicators, opinions, and tabs to act. The cure isn't more information, it's a simpler process you actually trust.

A false breakdown that lures traders into shorting, then reverses up and squeezes them. It works because fear makes people sell exactly where they should wait.

How much a stock moves relative to the overall market. A beta above 1 swings harder than the index; below 1 is steadier, a quick read on how wild a position will feel.

A false breakout that sucks in buyers, then reverses down and traps them. The clean-looking breakout that immediately fails is the classic bull trap.

Buying when the crowd is fearful and selling when it's greedy, betting the market overreacts. It's simple to say and brutal to do, because going against the herd feels wrong right up until it pays.

A short, sharp rally inside a larger downtrend that fools people into thinking the bottom is in. The bounce fades, the downtrend resumes, and the chasers are left holding it.

Spreading money across different assets so no single loss can sink you. It's the closest thing to a free lunch in investing, cutting risk without automatically cutting returns.

The drop from a portfolio's peak to its low before it recovers. Knowing your max tolerable drawdown ahead of time is what keeps a rough stretch from becoming a panic exit.

The average amount you can expect to win or lose per trade over time, blending win rate and reward-to-risk. A system can win less than half its trades and still print money if expectancy is positive.

A stock dropping fast and hard, tempting bargain hunters to catch it. Catching a falling knife is how accounts bleed; wait for it to hit the floor and stop moving first.

The largest peak-to-trough loss a strategy or account has suffered. It's the honest stress-test number, the pain you'd actually have had to sit through to earn the headline return.

When a stock has run too far, too fast from its moving averages and is stretched thin. Overextended moves snap back, and chasing them is buying right before the rubber band recoils.

Taking too many trades out of boredom, FOMO, or the urge to make money back. It quietly racks up fees and bad entries, usually the symptom of no clear plan.

Deciding how much to risk on a single trade, usually a small fixed percent of your account. It's the most underrated skill in trading: size wrong and one trade can undo months of good ones.

A scheme where promoters hype a cheap stock to inflate the price, then dump their shares on the buyers they lured in. If a stranger online is begging you to buy a tiny ticker, you're usually the exit liquidity.

Forcing trades to win back a loss, fast, while angry. It's the most expensive emotion after FOMO; the market doesn't owe you the money back, and it rarely pays up.

How much loss and volatility you can stomach without panic-selling at the worst possible time. Knowing yours before you buy is what keeps a rough week from turning into a permanent mistake.

How much you stand to gain versus lose on a trade, like 3:1. Stack the math in your favor and you can be wrong more often than right and still come out ahead.

A measure of return earned per unit of risk taken. It's how pros compare strategies honestly: a high raw return with a low Sharpe just means you got paid to gamble.

A sharp move engineered to trigger clustered stop-loss orders before price reverses. It's why placing your stop at the obvious round number is asking to get picked off.

The percentage of your trades that end in profit. It sounds like the headline stat, but a high win rate with tiny wins and huge losses is a slow-motion blowup, so pair it with reward-to-risk.