Financial Markets Glossary

Trading that occurs after a stock exchange's regular session closes. On US exchanges, after-hours trading typically runs from 4:00 PM to 8:00 PM Eastern Time via electronic communication networks (ECNs). Liquidity is lower and spreads are wider than during regular hours.

The lowest price at which a seller is willing to sell a security. When you buy a stock at the market, you pay the ask price. Also called the 'offer price'. The difference between the bid and ask is the bid-ask spread.

An order type that instructs a broker to execute a trade at the first available price when the market opens. Useful for traders who want guaranteed execution at the open but accept uncertainty about the exact fill price.

A market mechanism in which buyers and sellers simultaneously submit bids and offers, and trades execute when matching prices are found. Most major stock exchanges — including NYSE and LSE — open and close each session with a formal auction to establish the opening and closing prices.

One hundredth of one percent (0.01%). Commonly used to express changes in interest rates, bond yields, and spreads. For example, a rate rising from 5.00% to 5.25% is a 25 basis point increase.

A prolonged period of declining prices, generally defined as a fall of 20% or more from recent highs in a broad market index. Bear markets are often associated with economic contraction, rising unemployment, and falling corporate earnings.

The highest price a buyer is willing to pay for a security at a given moment. When you sell a stock at the market, you receive the bid price. The gap between bid and ask prices is called the spread.

The difference between the highest price a buyer will pay (bid) and the lowest price a seller will accept (ask). A narrow spread indicates a liquid, active market. A wide spread suggests thin liquidity and means it costs more to enter and exit positions — particularly common during pre-market, after-hours, or when a home market is closed.

A stock of a large, nationally recognized, financially sound company with a long track record of reliable performance. Examples include Apple, HSBC, and Toyota. The term originates from poker, where blue chips carry the highest value.

A period of rising market prices, typically defined as a gain of 20% or more from a recent trough. Bull markets are generally characterized by strong economic growth, low unemployment, and rising investor confidence.

A regulatory mechanism that temporarily halts trading when prices fall by a specified percentage within a session. US markets have three circuit breaker thresholds: 7%, 13%, and 20% drops in the S&P 500. Designed to prevent panic-driven crashes and allow traders time to assess information.

A process used by major exchanges at the end of each trading session to establish the official closing price for each listed security. During the closing auction, all outstanding orders are matched simultaneously at a single price that maximizes executed volume. The resulting price is used for index calculations, fund valuations, and portfolio benchmarking.

The normal mode of exchange operation during regular session hours, in which orders are matched and executed in real time as they arrive. Contrasts with auction-based trading, which happens at session open and close.

A private trading venue where institutional investors buy and sell large blocks of shares without displaying their orders publicly on an exchange. Dark pools reduce market impact for large trades but have drawn scrutiny over transparency concerns.

The practice of buying and selling financial instruments within a single trading session, closing all positions before the market closes. Day traders aim to profit from intraday price movements rather than holding overnight exposure.

The practice of advancing clocks by one hour during summer months to extend evening daylight. DST affects the UTC offset of markets in the US (Eastern Time) and Europe, causing their opening and closing times — expressed in UTC — to shift by one hour. Not all countries observe DST, which can temporarily change the overlap windows between sessions.

A display showing the number of open buy and sell orders at different price levels for a security. Also called the order book. A deep order book indicates high liquidity; a shallow book suggests that large orders could move the price significantly.

An automated system that directly connects buyers and sellers of securities, bypassing traditional exchange intermediaries. ECNs facilitate pre-market and after-hours trading on US exchanges and are widely used in forex markets. Examples include ARCA, BATS, and EDGX.

Shares of ownership in a corporation. When you buy equity (stock), you become a partial owner of the company and are entitled to a claim on its earnings and assets. Equities are the primary instruments traded on stock exchanges such as NYSE, LSE, and TSE.

An investment fund that holds a collection of assets — stocks, bonds, commodities, or a mix — and trades on an exchange like a single stock. ETFs offer diversification and typically lower fees than mutual funds. Popular examples include SPY (S&P 500), QQQ (NASDAQ-100), and GLD (gold).

The execution of a trading order. A complete fill means the entire order was executed; a partial fill means only a portion of the order was executed, often due to insufficient liquidity at the desired price.

The number of shares of a public company that are available for trading by the general public, excluding insider-held, restricted, or closely-held shares. A low-float stock can be highly volatile because relatively few shares are available to absorb buying or selling pressure.

The global market for trading national currencies against one another. Forex is the largest and most liquid financial market in the world, trading over $7 trillion per day. Unlike stock markets, forex operates 24 hours a day on weekdays, opening with the Sydney/Wellington session Sunday evening ET and closing with the New York session Friday afternoon.

Contracts that obligate the buyer to purchase — and the seller to deliver — an asset at a predetermined price on a specified future date. Futures are traded on exchanges and are widely used for hedging and speculation in commodities, indices, currencies, and interest rates. Equity index futures (such as ES for S&P 500) trade nearly 24 hours a day and can signal expected market direction before the cash equity session opens.

A gap occurs when a security opens significantly higher (gap up) or lower (gap down) than its previous closing price, with no trading in between. Gaps typically result from news, earnings releases, or macro events occurring outside regular trading hours — a direct consequence of markets being closed overnight.

A temporary suspension of trading in a specific security or an entire market. Trading halts can be triggered by significant news pending release, extreme price volatility (circuit breakers), or regulatory investigation. During a halt, no orders are executed until trading resumes.

A statistical measure representing the performance of a group of securities. Major stock indices include the S&P 500 (USA), FTSE 100 (UK), DAX (Germany), Nikkei 225 (Japan), and Hang Seng (Hong Kong). Indices provide a benchmark against which individual stocks and portfolios are measured.

Occurring within a single trading day. 'Intraday high' refers to the highest price reached during a session; 'intraday volatility' refers to price swings within the day. Intraday data is typically displayed on short-interval charts (1-minute, 5-minute, 15-minute).

The International Organization of Securities Commissions — the global standard-setter for securities regulation. IOSCO develops principles and standards that national regulators such as the SEC (USA), FCA (UK), and FSA (Japan) implement at the domestic level.

The ease with which a security can be bought or sold without causing a significant change in its price. A liquid market has many active participants, tight bid-ask spreads, and deep order books. Liquidity is highest during regular session hours — particularly during the London–New York overlap — and lowest outside trading hours.

An order to buy or sell a security at a specified price or better. A buy limit order will execute only at the limit price or lower; a sell limit order only at the limit price or higher. Limit orders give price certainty but not execution certainty.

The period — approximately 8:00 AM to 12:00 PM Eastern Time (1:00 PM to 5:00 PM GMT) — when both the London Stock Exchange and the New York Stock Exchange are simultaneously open. This four-hour window is the most liquid period of the global trading day, seeing the highest volumes in major currency pairs, equity indices, and other instruments that span both regions.

Borrowed capital that allows a trader to control a larger position than their cash balance would otherwise permit. Margin amplifies both gains and losses. Exchanges and brokers set minimum margin requirements; if a position moves against a trader and their equity falls below the maintenance margin, a margin call is issued requiring them to deposit additional funds.

The total market value of a company's outstanding shares, calculated by multiplying the share price by the number of shares outstanding. Companies are typically categorised as large-cap (over $10 billion), mid-cap ($2–10 billion), or small-cap (under $2 billion).

A firm or individual that continuously quotes buy (bid) and sell (ask) prices for a security, standing ready to trade at those prices. Market makers earn the spread and provide liquidity that allows other participants to buy or sell without waiting for a matching counterparty.

An order to buy or sell a security immediately at the best available price. Market orders guarantee execution but not price, making them less suitable in thin or fast-moving markets where the actual fill may differ significantly from the last quoted price (slippage).

A defined period during which an exchange is open for continuous trading. Most stock exchanges have a single regular session per day. Some also offer pre-market and after-hours sessions. The global trading day is often divided into the Asian, European, and North American sessions based on the geographic clustering of exchanges.

The tendency of an asset's price to continue moving in its current direction. Momentum traders buy securities that have been rising and sell those that have been falling, betting that existing trends will persist. Momentum strategies are often most effective during high-volume sessions when institutional participation is strong.

A process at the start of a trading session in which all orders accumulated since the previous close are matched simultaneously at a single price that maximises executed volume. The resulting price is the official opening price for the session.

An electronic list of all outstanding buy and sell orders for a security at different price levels, maintained by the exchange or ECN. The order book provides transparency into supply and demand. The top of the book — the best bid and ask — determines the current market price.

A difference between a security's closing price in one session and its opening price in the next session. Overnight gaps are caused by news, earnings, macroeconomic data, or events in other time zones that occur while the relevant exchange is closed. Gaps can be 'filled' later when price returns to the previous range, or can mark the start of a new trend.

Trading that occurs before a stock exchange's regular session opens. On US exchanges, pre-market trading typically runs from 4:00 AM to 9:30 AM Eastern Time via ECNs. Volume is lower and spreads are wider than during regular hours. News events and earnings releases before the open can create significant pre-market price moves.

The process by which buyers and sellers determine the fair price of an asset through their interactions in the market. Price discovery is most efficient when liquidity is high and many participants are active — such as during the regular session hours and particularly during the London–New York overlap.

The official, primary trading hours of a stock exchange — the window during which the greatest volume of trading occurs and official open/close prices are established. For the NYSE and NASDAQ, the regular session is 9:30 AM to 4:00 PM Eastern Time on weekdays.

A high-frequency trading strategy that aims to profit from very small price movements, often holding positions for seconds or minutes. Scalpers rely on tight spreads and high liquidity, making the active hours of major sessions the preferred operating window.

The process by which a trade is finalised — securities are transferred to the buyer and cash to the seller. Most global equity markets settle on a T+2 basis (two business days after trade date), though many have been transitioning to T+1. The settlement cycle means that a trade executed on Monday will typically settle on Wednesday.

Borrowing shares from a broker and selling them, with the intention of buying them back later at a lower price and returning them to the lender. Short sellers profit if the price falls. Short selling is restricted or regulated differently across exchanges worldwide.

The difference between the expected price of a trade and the price at which it is actually executed. Slippage is more common in fast-moving markets, during periods of low liquidity (pre-market, after-hours, or when the home exchange is closed), or when trading large quantities relative to available volume.

An order placed to sell a security automatically if its price falls to a specified level, limiting the investor's loss. Stop orders become market orders when the stop price is reached, so the actual fill may differ in fast or thin markets.

A medium-term trading strategy that holds positions from a few days to a few weeks, seeking to capture 'swings' in price within a broader trend. Swing traders are affected by overnight gaps and need to be aware of which sessions are active relative to their positions.

The standard settlement cycles for equities. T+2 means trades settle two business days after execution. Many markets — including the US — have moved or are moving to T+1 (next business day). The settlement cycle affects when cash and securities actually change hands and has implications for margin, dividends, and voting rights.

The minimum price movement of a security or contract. For US stocks, the minimum tick is $0.01. For futures contracts, tick sizes vary by product. The value of a tick depends on the contract size and price, and is important for calculating profit/loss in leveraged markets.

See 'Halted (Trading Halt)'.

See 'Market Session'.

A statistical measure of the dispersion of returns for a security or market index. High volatility means large price swings; low volatility means relatively stable prices. Implied volatility (derived from options prices) reflects the market's expectation of future price movement. The VIX index measures implied volatility for the S&P 500.

The total number of shares, contracts, or units of a security traded during a specific period. Volume is a key indicator of market activity and liquidity. A price move accompanied by high volume is generally considered more significant than one on low volume.

The average price of a security weighted by trading volume throughout the day. Institutional traders and algorithms commonly use VWAP as a benchmark — executing orders to achieve a fill close to VWAP minimises market impact. A price above VWAP is often considered bullish intraday; below is bearish.

The income return on an investment, expressed as a percentage of its cost or current market value. For stocks, yield refers to the dividend yield. For bonds, it refers to the interest income relative to price. Yields and prices move inversely for fixed-income instruments.