Getting started: US market structure: glossary

  • Room 01
  • 27 terms

The terms

  • Brokerage accountA brokerage account is an account with a registered broker that records the securities you own while a custodian holds the actual shares. It is the…
  • CboeCboe is the Chicago-based exchange group that runs the largest US options market and four US stock exchanges grown out of BATS, an exchange built by…
  • CFTCThe CFTC is the Commodity Futures Trading Commission, the US referee for futures, swaps and anything shaped like a contract on a price. It publishes…
  • Closing auction (official close)The closing auction is the single matched trade at 1:30 AM IST, 2:30 AM in winter, that sets each US stock's official closing price, about a tenth…
  • CME GroupCME Group is the Chicago exchange where futures on US stock indices, interest rates, gold, oil and copper trade, through COMEX and NYMEX among…
  • CustodianA custodian is the institution that holds securities or assets for a broker's clients, kept apart from the broker's own money. For any claim the…
  • Dark poolA dark pool is a private trading venue where orders stay hidden until they fill, so a fund can move a large block without showing its hand on the…
  • Designated market makerA designated market maker is the one firm the NYSE assigns to each listed stock to keep trading orderly and to run its opening and closing auctions.…
  • Dow Jones Industrial AverageThe Dow Jones Industrial Average is thirty large American companies averaged by share price, not by size, since 1896. A four hundred dollar stock…
  • FINRAFINRA is the Financial Industry Regulatory Authority, US brokers policing themselves under the SEC. It writes broker rules like the pattern day…
  • Fractional sharesFractional shares let you own part of one share, say 0.1 of a $500 stock, through a broker that holds whole shares and splits them on its own books.…
  • IEXIEX is the US stock exchange that delays every order by 350 microseconds through a coil of fibre, so it can update its own prices before anyone…
  • Limit up-limit downLimit up-limit down is the US single-stock speed limit: a band around the recent price, 5% either side for large stocks and 10% for the rest. If the…
  • NASDAQNasdaq is the American exchange that began in 1971 as one screen showing every dealer quote side by side, the first market with no floor. Most…
  • Nasdaq 100The Nasdaq 100 is an index of the hundred largest non-financial companies listed on Nasdaq, weighted by market value and dominated by technology. It…
  • NBBOThe NBBO, national best bid and offer, is the highest bid and lowest ask for a US stock across every exchange at once. Since 1975 the venues have…
  • NYSEThe NYSE is the New York Stock Exchange, started in 1792 when twenty four brokers agreed to trade only with each other. Most large, old American…
  • NYSE ArcaNYSE Arca is the fully electronic NYSE exchange where most US ETFs list, around three quarters of ETF assets as of 2026. It is one of the twenty-odd…
  • Opening auctionThe opening auction is the single trade that starts the US day at 7:00 PM IST, 8:00 PM in winter. Orders collect before the bell, one price is…
  • Overnight session (24-hour stock trading)The overnight session is US stock trading through the American night, which is the Indian working day, on a handful of venues approved from 2024.…
  • Payment for order flowPayment for order flow is a wholesaler paying a retail broker to send it customer orders, which it fills inside its own system at the national best…
  • Pre-market and after-hours tradingPre-market and after-hours are the thin sessions around the US day: pre-market from 1:30 PM IST, after-hours until 5:30 AM IST, an hour later from…
  • Russell 2000The Russell 2000 is about two thousand smaller American listed companies, the standard measure of US small caps. They borrow more at floating rates…
  • S&P 500The S&P 500 is about five hundred of the largest American companies, weighted by market value, and the number money is measured against. Index funds…
  • SECThe SEC is the US Securities and Exchange Commission, the referee Congress built after 1929 exposed how little buyers knew. It can halt a stock, sue…
  • Ticker symbolA ticker symbol is the short code an exchange gives a listed security: NVDA for Nvidia, AAPL for Apple. Nasdaq tickers usually run four letters and…
  • Trading haltA trading halt freezes a US stock on every exchange at once. A news halt lets everyone read an announcement before anyone trades on it; a limit…