Trading glossary.

The highest price a buyer is currently willing to pay. Market sell orders fill at the bid.

The lowest price a seller is currently willing to accept. Market buy orders fill at the ask.

The difference between the bid and ask. Tighter spreads indicate deeper liquidity. The spread is the immediate cost of a market order.

An order to buy or sell immediately at the best available price. Takes liquidity from the book. Guarantees execution but not price.

An order to buy or sell at a specific price or better. Adds liquidity to the book. Guarantees price but not execution.

An order that triggers a market or limit order once price reaches a specified level. Used for entries on breakouts or to exit losing positions.

The ease with which an asset can be bought or sold without significantly moving its price. Measured by depth, spread, and volume.

The difference between the expected fill price and the actual fill price. Worse in thin markets, during news, and with large orders relative to available liquidity.

A position that profits when price rises. Bought but not yet sold.

A position that profits when price falls. Borrowed and sold with the intent to buy back at a lower price.

The number of contracts, shares, or units held. Determines the dollar value of each tick or point of price movement.

The price at which a trade is opened. Defines the reference point for all subsequent stop, target, and risk calculations.

The price at which a trade is closed. Can be at a profit target, a stop loss, or discretionary based on changing conditions.

A predefined exit point that limits the maximum loss on a trade. Not a prediction device — a risk containment mechanism.

A predefined exit point that closes a winning trade automatically. Prevents giving back gains when you're unavailable to manage.

The peak-to-trough decline in account equity over a period. A key measure of strategy risk and psychological durability.

Profit and loss. Often broken into realized (closed) and unrealized (open). Managing unrealized PnL psychologically is a core skill.

The minimum price increment of an instrument. In ES futures, one tick = 0.25 points = $12.50 per contract.

A standardized unit of a derivative instrument. Each futures contract has a fixed notional value and tick size defined by the exchange.

The collateral required to hold a leveraged position. Initial margin opens the trade; maintenance margin is the minimum to keep it open.

Controlling a larger notional position with a smaller deposit. Amplifies both gains and losses proportionally.

The process of finalizing a trade. Cash settlement pays the difference in cash; physical settlement delivers the underlying asset.

Moving a futures position from the expiring front month to the next active contract. Volume migrates before expiry, creating a shift in continuous charts.

A price peak where the bar high is higher than the highs of the bars on both sides. Used to define trend direction and potential reversal zones.

A price trough where the bar low is lower than the lows of the bars on both sides. The counterpart to swing highs in defining trend structure.

A swing high that exceeds the previous swing high. Characteristic of bullish trend structure.

A swing low that is above the previous swing low. Confirms buying interest on pullbacks and intact bullish structure.

A swing low that undercuts the previous swing low. Characteristic of bearish trend structure.

A swing high that fails to reach the previous swing high. Confirms selling pressure on bounces and intact bearish structure.

Price breaking through a significant swing high or low in the direction of the current trend. Confirms continuation of existing structure.

Price breaking through a swing point counter to the prevailing trend, signaling a potential reversal of structure rather than continuation.

A deliberate manipulation of retail stop orders at obvious swing levels before price reverses. Smart money uses retail predictability to build positions cheaply.

The last consolidation candle before an impulsive move away from a level. Represents where institutional orders were placed. Price often returns to these zones.

A three-candle pattern where the middle candle leaves a gap unfilled by the wicks of the surrounding candles. Represents inefficiency that price tends to revisit.

An area where aggressive buying or selling left price moving so fast that the opposite side wasn't present. Creates unfilled zones that act as future magnets.

A concentration of stop orders sitting above a swing high or below a swing low. Institutional traders target these to fill large orders.

An order block that fails to hold price and is broken through. The failed order block often becomes a support or resistance zone on the opposite side.

A candle pattern where price returns to the origin of an impulse move to "mitigate" the imbalance left by the initial move before continuing.

The upper half of a measured price range. Selling from premium and buying from discount is a core ICT market structure concept.

The lower half of a measured price range. Institutions buy in discount and sell in premium, the opposite of retail behavior at extremes.

A defined price area between a recent swing high and swing low where price oscillates without establishing a clear trend direction.

A period of reduced volatility where price moves sideways. Represents an agreement between buyers and sellers before one side capitulates.

A framework describing markets as continuous two-sided auctions. Price moves to facilitate trade — when trade stops at a level, the auction moves to find a new price where trade resumes.

The price range containing 70% of the session's volume, derived from the volume profile. Defines the zone where the majority of fair-value business was done.

The upper boundary of the value area. Represents the top of accepted fair value. Price above VAH is in premium relative to the session.

The lower boundary of the value area. Represents the bottom of accepted fair value. Price below VAL is in discount relative to the session.

The price level with the most volume traded in a given period. The single most agreed-upon fair price. Acts as a magnet when price is away from it.

A state where buyers and sellers broadly agree on value. Price moves horizontally within a defined range. Represents two-timeframe trader activity in equilibrium.

A state where one side of the auction dominates and price trends directionally. Buyers or sellers are willing to transact only at higher or lower prices, creating a one-timeframe market.

Directional buying above the previous value area or directional selling below it. The participant initiating the move, not reacting to it.

Buying below value or selling above value — fading price that has moved away from fair value. The responsive participant believes the move was excessive.

Two or more consecutive time periods trading at or through a level, indicating that market participants have accepted the new price as fair value.

Price moves to a new level but finds no trade facilitation there, snapping back quickly. The market is communicating that the new price is not fair.

An area between the prior session's close and the current session's open with no volume traded. An unfilled gap is an unfinished auction that price will often return to fill.

A sharp, decisive move away from an extreme, signaling the market has gone too far and is rejecting that price. Long tails/wicks on market profile indicate excess.

Price breaks out of a prior balance area or key level but fails to develop new value and returns inside. A strong contra-trend signal when confirmed.

The gradual shift of the value area from one price level to another over multiple sessions. Indicates directional conviction from participants with longer time horizons.

Two or more sessions whose value areas overlap significantly. Indicates ongoing balance between sessions — neither side has gained meaningful ground.

A histogram of volume traded at each price level over a specified period. Unlike time-based volume bars, it shows WHERE volume occurred, not just when.

Price levels with significantly more volume than surrounding levels. Represent fair value zones where a lot of business was done. Act as magnets and support/resistance.

Price levels with significantly less volume than surrounding levels. Represent price rejection — the market moved through quickly with little acceptance. Often act as inflection points.

A flat, wide horizontal cluster of volume at a particular price zone. Represents extended balance and is often a significant decision point if revisited.

Volume-weighted average price. The average price weighted by volume for the session. Institutions benchmark execution quality against VWAP; it acts as an intraday fairness reference.

VWAP calculated from a specific starting event — a high, low, gap, earnings report, or major swing. Particularly useful for identifying institutional cost basis from key events.

A volume profile drawn over a manually selected price range. Used to analyze specific balance areas, prior consolidations, or custom date ranges.

A volume profile built across multiple sessions or a longer time window. Shows the broader structure of where volume has concentrated across days, weeks, or months.

A grouping of high-volume nodes within a narrow price range. Represents strong institutional interest and often forms reliable support or resistance on return visits.

The point of control as it shifts in real time during an active session. Monitoring POC migration reveals whether participants are building new value or defending old levels.

The overall outline of a volume profile. P-shape (heavy top) suggests trapped shorts; b-shape (heavy bottom) suggests trapped longs; D-shape (balanced) suggests two-sided trade.

A prior session's point of control that has not been revisited by subsequent price action. These unvisited POCs act as magnets and are high-probability target zones.

The actual stream of buy and sell orders hitting the market. Order flow analysis reads the real-time interaction between aggressive takers and passive liquidity providers.

A market participant who submits a market order and takes liquidity. Aggressors move price. They are willing to pay the spread to transact immediately.

A market participant who posts limit orders and provides liquidity. Passive orders wait for aggressors to come to them. They earn the spread but accept execution risk.

Buy volume minus sell volume over a period. Positive delta means more aggressive buying; negative delta means more aggressive selling. Divergence between delta and price reveals hidden intent.

The running sum of delta over multiple periods. A persistent divergence between cumulative delta and price often precedes a correction in the direction of the delta.

A level where large passive limit orders absorb aggressive flow without letting price move. Heavy buy volume at a level with no upward movement indicates sellers absorbing the aggression.

A surge in aggressive order flow that fails to produce commensurate price movement. The aggressors have run out of fuel — a reversal or slowdown often follows.

Multiple consecutive price levels where buy volume significantly exceeds sell volume (or vice versa). Represents strong directional conviction from aggressors across a price range.

The real-time stream of time and sales prints. Reading tape means observing the speed, size, and aggression of transactions as they occur.

A large order split into smaller visible tranches. Only a portion is shown on the DOM; as tranches are filled, new ones are refreshed. Designed to hide institutional order size.

Aggressive orders that consume multiple levels of liquidity in succession. A liquidity sweep signals strong directional intent from the initiating participant.

The total number of outstanding futures or options contracts not yet settled. Rising OI on a move confirms new money entering; falling OI suggests liquidation.

Participants holding losing positions who will be forced to exit if price moves against them. Their eventual stop-loss orders become fuel for the move.

A sharp move through a liquidity level, triggering stop orders. Often followed by a reversal once the stops are cleared and aggressive order flow exhausts.

Roughly balanced aggressive buying and selling. Price stays contained. Indicates neither side has conviction — consistent with balance or consolidation context.

A candlestick variant that displays bid and ask volume at each price level within every bar. Shows not just price movement but the order flow that drove it.

Each row in a footprint bar showing sell volume at bid (left) and buy volume at ask (right) for that specific price level. The fundamental data unit of footprint analysis.

A cell where buy volume (ask) is significantly larger than sell volume (bid) at the level above it. Typically highlighted when the ratio exceeds 3:1 or a user-defined threshold.

A cell where sell volume (bid) is significantly larger than buy volume (ask) at the level below it. Indicates aggressive selling overwhelmed passive buyers at that level.

A bar that closes with volume only on one side of the extreme (bid at the low, ask at the high). The other side was never tested — the auction remains incomplete.

When price makes a new high or low but delta does not confirm the move. Suggests the directional aggression is weakening while price extends — a precursor to reversal.

A footprint bar with significantly more total volume than surrounding bars. Indicates a high-activity period where institutions are participating heavily.

A footprint bar where large bid or ask volume is present but price barely moves. The aggressive side was absorbed by passive orders — a strong contra-trend signal.

Within a footprint, alternating control between buyers and sellers across multiple price levels. Indicates two-sided trade with no clear directional conviction.

Price levels within a footprint bar with notably high total volume. These nodes within individual bars hint at institutional activity at those specific prices.

A real-time display of resting limit orders at each price level on both the bid and ask. Shows the quantity of contracts available at each price before the market.

The complete list of outstanding buy and sell limit orders for an instrument, sorted by price. The DOM is the visible portion of the order book.

A concentration of large limit buy orders at a specific price level. When large bid stacks appear, the market often slows or reverses there — but they can also be fake.

A concentration of large limit sell orders at a specific price level. Acts as overhead resistance. Can slow advances but is also frequently used as a spoofing tool.

Placing multiple large orders at different price levels on one side of the book to create a false impression of supply or demand. A form of market manipulation.

Placing and quickly canceling large orders to mislead other participants about supply or demand. Illegal in regulated markets but difficult to detect in real time.

The rapid cancellation of large DOM orders before price reaches them. Often seen when a large "wall" disappears just before price arrives, allowing the move to continue through.

Large orders that are continuously refilled as they are consumed. Unlike spoofed orders, refreshing orders represent genuine passive liquidity — they sustain a level.

A DOM with very few resting orders. Price can move quickly through thin areas with minimal volume. Often appears near major price extremes or before news events.

The imbalance between total bid quantity and total ask quantity across the DOM. Large bid pressure suggests buyers outnumber sellers at current prices, and vice versa.

The speed at which orders are consumed on the DOM. High velocity indicates strong aggression; slow, deliberate consumption indicates absorption or methodical institutional activity.

A price level where buying interest has previously been strong enough to halt a decline. Not a guaranteed floor — once broken convincingly, prior support often becomes resistance.

A price level where selling interest has previously been strong enough to halt an advance. Once broken convincingly, prior resistance often becomes support.

A diagonal line connecting a series of swing highs or lows. Used to visualize trend direction and identify potential areas of future interest. Subject to interpretation.

The average price over a rolling lookback period. Smooths price data to reveal trend direction. Common periods: 9, 20, 50, 100, 200. SMA is simple; EMA weights recent data more heavily.

A momentum oscillator scaled 0-100. Readings above 70 indicate overbought; below 30 indicate oversold. Divergence between RSI and price is more useful than absolute levels.

Moving Average Convergence Divergence. The difference between two EMAs, with a signal line. Crossovers indicate potential momentum shifts; histogram shows the rate of change.

Key retracement levels (23.6%, 38.2%, 50%, 61.8%, 78.6%) drawn from a significant swing. Used as potential support/resistance zones during pullbacks. Works because many traders use them.

A moving average with upper and lower bands set at 2 standard deviations. Bands expand during volatility, contract during calm. Price at bands alone is not a signal.

A volatility measure showing the average range of recent bars. Used to size stops relative to normal market movement, not arbitrary fixed levels.

A price bar showing open, high, low, and close. The body shows the open-to-close range; wicks extend to the session high and low. Each candle is a compressed story of supply and demand.

A candlestick where open and close are nearly equal, resulting in a minimal body. Signals indecision. Meaningful only in context of the surrounding trend and volume.

A two-candle pattern where the second bar's body fully engulfs the first. Bullish engulfing at lows and bearish engulfing at highs are classic reversal signals when volume confirms.

When the opening price is above the prior session's high (gap up) or below the prior session's low (gap down). Often driven by news or earnings. Unfilled gaps act as reference levels.

A recurring price formation with historical predictive value — head and shoulders, double top/bottom, wedge, triangle, flag. Validity requires volume and context, not just shape.

The ratio of potential profit to potential loss on a trade. A 2:1 R:R means you risk $1 to make $2. Even a 40% win rate can be profitable with sufficient R:R.

Expressing trade outcomes as multiples of initial risk. A trade that made $300 with a $100 stop was a 3R winner. Normalizes results across different position sizes.

The percentage of trades that close profitably. Win rate alone means nothing without knowing average winner vs average loser size — these must be analyzed together.

The average profit per trade over many trades: (Win Rate × Avg Win) - (Loss Rate × Avg Loss). Positive expectancy is necessary for long-term profitability.

The largest peak-to-trough decline in account equity. A key metric for evaluating strategy robustness. Both magnitude and duration matter.

The fixed or percentage-based dollar amount risked on a single trade. Keeping this consistent is the foundation of position sizing discipline.

A formula for calculating optimal position size based on win rate and R:R. In practice, traders use fractional Kelly (25-50%) to account for estimation errors and reduce ruin risk.

The risk of holding multiple positions that move together. Appearing diversified but being heavily correlated means a single market event can hit all positions simultaneously.

The risk of extreme, low-probability events that fall outside normal statistical distributions. Black swans. Sizing and hedging must account for scenarios beyond the historical norm.

The probability of losing enough capital that recovery is mathematically or practically impossible. The paramount concern. Controlling position size keeps ruin risk near zero.

Return divided by the standard deviation of returns, adjusted for the risk-free rate. A higher Sharpe indicates better risk-adjusted returns. A ratio above 1 is generally considered solid.

Like the Sharpe but only penalizes downside volatility. More appropriate for strategies with asymmetric return profiles where upside volatility is desirable.

The total monetary value of all goods and services produced in a country over a period. Two consecutive quarters of negative GDP growth is the technical definition of a recession.

A sustained increase in the general price level of goods and services, eroding purchasing power. Measured by CPI, PPI, and PCE. The primary target variable for central bank policy.

A measure of inflation tracking the average price change of a basket of consumer goods and services. Core CPI excludes food and energy for a less volatile reading.

Measures wholesale price changes at the producer level. Often considered a leading indicator of CPI — producer cost increases tend to pass through to consumers with a lag.

The Fed's preferred inflation measure. Broader than CPI and adjusts for consumer substitution behavior. Core PCE (ex food and energy) drives most Fed policy decisions.

The monthly count of jobs added or lost in the US economy excluding farming, government, and non-profits. The single most market-moving scheduled data release.

The percentage of the labor force actively seeking work but unable to find it. A lagging economic indicator — it peaks after a recession has already begun.

The central bank of the United States. Sets the federal funds rate and conducts monetary policy to pursue its dual mandate: maximum employment and price stability.

The target interest rate at which banks lend to each other overnight. The Fed's primary policy tool. Affects borrowing costs across the entire economy.

Federal Open Market Committee. The Fed body that sets monetary policy and meets eight times per year. FOMC meeting days are among the highest volatility days for US markets.

A central bank policy of buying financial assets (typically bonds) to inject money into the economy and lower long-term interest rates. Tends to inflate asset prices.

The reverse of QE. The central bank reduces its balance sheet by letting bonds mature without reinvestment or selling assets outright. Withdraws liquidity from the system.

A market environment where participants favor higher-risk assets — equities, high-yield bonds, emerging markets, commodities. Associated with economic expansion and confidence.

A market environment where participants flee to safety — Treasuries, gold, USD, JPY. Associated with economic uncertainty, geopolitical events, or financial stress.

A monthly survey-based indicator of business activity. Above 50 indicates expansion; below 50 indicates contraction. Considered a leading indicator of economic direction.

A significant, widespread, and extended decline in economic activity. Technically defined as two consecutive quarters of negative GDP growth. Characterized by rising unemployment and falling output.

A debt instrument representing a loan from the buyer to the issuer. The issuer pays periodic interest (coupon) and returns the principal at maturity. Price and yield move inversely.

The return on a bond expressed as an annual percentage. As bond prices rise, yields fall. As bond prices fall, yields rise. This inverse relationship is fundamental to fixed income.

A graph plotting yields of bonds with the same credit quality across maturities. The shape signals economic expectations: normal (upward sloping), inverted (short rates above long), flat.

When short-term yields exceed long-term yields. Has preceded every US recession over the past 50 years, though with variable lead times of 6 to 24 months.

A measure of a bond's sensitivity to interest rate changes. A duration of 7 means roughly a 7% price change for every 1% change in interest rates. Longer duration means more rate sensitivity.

The periodic interest payment on a bond, expressed as a percentage of face value. A 5% coupon on a $1,000 bond pays $50 per year regardless of market price.

The yield difference between a corporate bond and a comparable Treasury bond. Wider spreads signal increased perceived default risk or tighter market liquidity conditions.

US government debt securities. T-bills (under 1 year), T-notes (2-10 years), T-bonds (20-30 years). Considered risk-free for credit purposes; prices fluctuate with interest rate expectations.

The yield difference between the 10-year and 2-year Treasury. A closely watched recession indicator. When the 2-year yields more than the 10-year, the curve is inverted.

The iShares 20+ Year Treasury Bond ETF. A common proxy for long-duration Treasury exposure. Highly sensitive to long-end yield moves — traders use it to express duration views.

Corporate bonds rated below investment grade (below BBB-/Baa3). Offer higher yields to compensate for greater default risk. Spreads over Treasuries are a key risk appetite indicator.

Bonds rated BBB-/Baa3 or above by S&P/Moody's. Lower default risk, lower yields. Many large institutions are restricted to holding only investment grade debt.

Ownership in a company, represented by shares of stock. Equity holders have a residual claim on assets and earnings after all debts are paid.

Net income divided by shares outstanding. A measure of profitability on a per-share basis. Earnings beats and misses relative to analyst estimates are the primary earnings reaction driver.

Share price divided by earnings per share. The most common valuation multiple. A high P/E implies the market expects strong future growth; a low P/E can indicate undervaluation or poor prospects.

Share price divided by revenue per share. Used for companies without positive earnings. More stable than P/E but doesn't account for profitability.

A valuation method estimating the present value of future cash flows. The discount rate used is crucial — small changes create large valuation differences. Highly sensitive to growth assumptions.

Total income generated by a company before any expenses. Top-line growth is the primary driver of long-term valuation expansion in high-growth businesses.

A company's own forward-looking projections for future revenue, earnings, or margins. Markets often react more to guidance changes than to actual reported results.

A quarterly conference call where management discusses financial results and answers analyst questions. Tone, language, and guidance language drive post-earnings price action.

The flow of institutional money between market sectors (technology, energy, financials, healthcare, etc.) in response to changing economic conditions and rate expectations.

Total market value of a company's outstanding shares. Share price multiplied by shares outstanding. Determines index weighting and institutional eligibility thresholds.

Cash generated by a business after accounting for capital expenditures. Often considered more reliable than accounting earnings. Companies with strong FCF have more options for capital allocation.

A durable competitive advantage that protects a company from competition — network effects, switching costs, brand power, cost advantages, or regulatory barriers.

The total number of shares currently sold short as a percentage of float. High short interest can create short squeezes when positive news forces short sellers to cover.

The total number of shares available for public trading. Lower float stocks are more volatile because a smaller supply of shares absorbs the same buying or selling pressure.

A contract to buy or sell an asset at a specific price on a future date. Standardized and exchange-traded. Used for speculation, hedging, and institutional risk management.

A contract giving the holder the right (not obligation) to buy (call) or sell (put) an asset at a set price before a specific date. Premium paid upfront; potential loss limited to premium for buyers.

An option giving the buyer the right to purchase the underlying asset at the strike price. Profitable when underlying price rises above strike plus premium paid.

An option giving the buyer the right to sell the underlying asset at the strike price. Used for downside protection or bearish speculation.

The predetermined price at which an option can be exercised. In-the-money (ITM), at-the-money (ATM), or out-of-the-money (OTM) relative to the current underlying price.

The price paid to buy an option. Consists of intrinsic value (moneyness) and time value (extrinsic). Premium decays as expiration approaches — this is theta.

The CBOE Volatility Index. Measures the 30-day implied volatility of S&P 500 options. Often called the "fear index." Readings above 30 indicate elevated fear; below 15 indicate complacency.

The market's forward-looking estimate of volatility embedded in option prices. High IV means options are expensive; low IV means they're cheap. IV tends to rise during uncertainty and fall after events.

The number of put options traded divided by call options traded. High ratios indicate bearish sentiment; very high ratios can be contrarian bullish signals and vice versa.

A weekly CFTC report showing net positions of commercial hedgers, large speculators, and small speculators in futures markets. Extreme positioning can precede reversals.

The rate of change of an option's delta for a $1 move in the underlying. High gamma means the delta changes rapidly — relevant for market makers who must hedge dynamically.

When heavy call option buying forces market makers to buy the underlying to delta-hedge, which pushes price higher, which forces more buying — a self-reinforcing feedback loop.

CNN's composite sentiment indicator built from 7 factors including momentum, safe haven demand, junk bond spreads, and options positioning. Useful as a contrarian extreme-reading tool.

A futures market state where contracts further from expiry are priced higher than near-term contracts. Normal for most commodities due to storage costs. Creates "roll yield drag" for long holders.

A futures market state where near-term contracts are priced higher than longer-dated ones. Indicates tight spot supply or strong current demand. Beneficial for long rolling strategies.

The study of how financial markets operate at the transaction level — the mechanics of order submission, price formation, and how information gets incorporated into prices.

A firm or individual that continuously quotes both bid and ask prices, providing liquidity to the market. Earns the spread as compensation for the inventory and adverse selection risk they accept.

The risk that a market maker or passive trader is on the wrong side of an informed trader. When someone wants to trade urgently, they often know something the passive side doesn't.

A participant trading on private or superior information. Their order flow is a signal that gets incorporated into prices. Market makers widen spreads in the presence of informed flow.

A participant trading on non-informational reasons — liquidity needs, emotional reactions, technical signals. Their flow doesn't persistently move prices but provides cover for informed traders.

The amount by which an order moves the market price. Larger orders have greater price impact. Market impact models help institutions estimate execution costs before trading.

An execution algorithm that breaks a large order into equal slices over a specified time window. Minimizes market impact by spreading execution across time.

An algorithm that executes a large order proportional to market volume throughout the day. Benchmarks execution quality against the session VWAP — the standard institutional metric.

Algorithmic trading strategies operating at microsecond to millisecond timescales. Strategies include market making, statistical arbitrage, and latency arbitrage. HFT firms are the dominant liquidity providers.

Exploiting speed advantages to trade on stale prices before market makers can update their quotes. Co-location and direct market access minimize latency to gain this edge.

A private trading venue not displayed on public order books. Large institutional orders are executed here to avoid price impact. Prints appear on the tape after execution.

A public exchange where all bid and ask orders are visible pre-trade. Exchanges like NYSE, Nasdaq, and CME are lit markets. Contrasted with dark pools and internalization.

When a broker fills a customer order against its own inventory or another customer order without routing to an exchange. Payment for order flow (PFOF) is a form of internalization.

Placing trading servers physically adjacent to exchange matching engines to reduce latency. Renting co-location space is necessary for any latency-sensitive algorithmic strategy.

The exchange's core software that matches buy and sell orders. Price-time priority is the most common matching rule: orders at the same price fill in the order they were submitted.

The real-time record of every transaction: time, price, size, and whether it was a buy or sell aggressor. The raw data underlying tape reading and footprint charts.

Sending a massive number of orders and cancellations rapidly to slow down competitors' systems. A controversial HFT tactic that degrades market quality for other participants.

Orders that are submitted and canceled within milliseconds. Represent the majority of all order flow by message count. Inform the book but rarely execute.

A written ruleset defining entry conditions, exit conditions, position sizing, risk limits, and markets traded. Following a plan makes performance measurable and improvable.

Distinguishing between the quality of a decision and the quality of the result. A good process can produce a bad outcome and vice versa. Evaluating process, not outcomes, is the correct feedback loop.

Entering trades to recover a loss, typically by increasing size or abandoning the trading plan. Compounds losses and is one of the most destructive behaviors in trading.

Entering a trade after the move has already occurred because you fear missing further gains. Leads to buying tops and selling bottoms — poor entry timing driven by emotion rather than edge.

Taking more trades than your edge warrants. Often driven by boredom, need for excitement, or an attempt to force results. More trades does not mean more profit if the additional trades have no edge.

Seeking and favoring information that confirms your existing view. Leads to ignoring disconfirming data and holding trades beyond rational exit points.

The psychological tendency to feel the pain of a loss more intensely than the pleasure of an equivalent gain (roughly 2:1). Leads to holding losers too long and cutting winners too short.

Over-weighting the first piece of information received (your entry price, an analyst target, a round number) when making decisions. Price doesn't know or care where you entered.

A record of every trade including entry, exit, setup, rationale, and emotional state. The primary tool for self-improvement. Patterns in losses and mistakes only become visible with consistent logging.

Overweighting recent events in predictions. After a winning streak, expecting it to continue; after a losing streak, expecting further losses. Both distort rational probability assessment.

The compulsion to enter at the absolute high or low of a move. Leads to missed entries waiting for a perfect level and frustration when price doesn't return. Good enough entries beat perfect entries that never come.

The number of trades needed to evaluate a strategy's edge with statistical significance. A losing week or even month tells you almost nothing. Hundreds of trades establish meaningful patterns.