Trading Mechanics
Between clicking an order and owning a position sits a surprising amount of machinery, and this category covers all of it.
The explainers run through every order type, from market and limit to stop, stop-limit, and the on-close and on-open variants, plus time-in-force rules like GTC and IOC, then the order book, the bid-ask spread, margin, short selling, settlement, and market structure.
Investing With Purpose shows how each execution choice feeds back into cost and risk, and why microstructure matters even to investors who hold for years.
Understand this category and you trade deliberately, with a clear picture of exactly what happens to an order once it leaves your hands.
A market order tells your broker to buy or sell a stock immediately at the best available price. It prioritizes speed…
A limit order tells your broker to trade only at a specific price or better. You trade price certainty for the chance…
A stop order is a resting instruction that converts to a market order the moment a stock trades at a specified stop…
A stop-limit order converts to a limit order, not a market order, when its stop price is triggered. You get price…
A trailing stop is a stop order whose trigger price follows the stock as it moves in your favor, then locks in place if…
A One-Cancels-Other (OCO) order links two exit instructions so that filling one automatically cancels the other. A…
Time-in-force (TIF) is the instruction that tells your broker how long an order should stay active. The same limit…
The bid-ask spread is the gap between the highest price a buyer is willing to pay and the lowest price a seller is…
The order book is the live list of buy and sell limit orders resting at an exchange, sorted by price. Market depth is…
The settlement cycle is the number of business days between the trade date and the day ownership and cash actually…
Tick size is the smallest amount a security's quoted price can move. Lot size is the smallest or standard unit in which…
A brokerage account is an investment account you open with a licensed firm to buy and sell securities such as stocks,…
Opening a brokerage account is the first practical step toward investing, and it is faster than most beginners expect.…
When you open a brokerage account, you choose between two settlement types: a cash account or a margin account. The…
A stock quote is the snapshot of price information you see before you trade. At first it looks like a wall of numbers,…
Placing your first trade can feel intimidating, but the order screen is just a short form. You tell the broker what to…
An order ticket is the form you fill out to place a trade. Every broker arranges it a little differently, but the…
When you buy or sell a stock, the trade executes in seconds, but the final exchange of shares and cash takes a little…
Trading is rarely entirely free, even when a broker advertises "zero commission." The costs are simply spread across…
Dark pools are private trading venues where buy and sell orders are matched without displaying quotes to the public…
Payment for order flow is the practice where a market maker pays a retail broker to route that broker's customer orders…
Short selling is the practice of borrowing shares, selling them at the current market price, and buying them back later…
Short interest is the total number of shares that have been sold short and not yet covered. Days to cover expresses…
A margin account lets you borrow from your broker to buy more securities than your cash would allow. Regulation T, a…
Maintenance margin is the minimum equity you must keep in a margin account after the trade is on. When equity drops…
A trading halt is a temporary pause in the trading of a security. The two main families are single-stock halts driven…
To sell a stock short, your broker must first borrow the shares. When supply is scarce, the borrow costs money,…
Circuit breakers are automatic trading halts triggered by large moves in a broad equity index. The US system pauses the…
Securities lending is the plumbing that makes short selling and many derivatives strategies possible. A long-term…
Before a broker can accept a short sale order, US rules require it to have reasonable grounds to believe the security…
Index reconstitution is the scheduled process where index providers add new names, drop falling ones, and adjust…
In the maker-taker fee model, an exchange pays a **rebate** to traders who post resting limit orders that add liquidity…
The National Best Bid and Offer (NBBO) is the highest publicly displayed bid and the lowest publicly displayed offer…
A limit order is an instruction to buy or sell a security only at a specified price or better. It gives you control…
A market order is an instruction to buy or sell a security immediately at the best price currently available. It…
A stop order is an instruction that stays dormant until a stock reaches a chosen trigger price, at which point it…
A stop-limit order combines two instructions: a stop price that wakes the order up and a limit price that caps the…
A market on close order MOC is an instruction to buy or sell at the official closing price set by the exchange's…
A market on open order MOO is an instruction to buy or sell at the official opening price set by the exchange's opening…
A limit on close order LOC participates in the closing auction but only fills if the official closing price is at or…
A limit on open order LOO participates in the opening auction but only fills if the official opening price is at or…
A good till canceled order GTC stays active across multiple trading sessions until it executes or you cancel it. It is…
An immediate or cancel order IOC fills as much of your order as it can right away and cancels any portion that cannot…
A fill or kill order FOK must execute its entire size immediately or be canceled in full. It allows no partial fills…
An all or none order AON must execute its full quantity or none at all, but unlike fill-or-kill it does not demand…
A market if touched order MIT rests quietly until the price reaches a level you choose, then converts into a market…
The Nasdaq PHLX options exchange is one of the largest US venues for listed options, and one of only a handful that…
The CUSIP vs ticker symbol distinction is the difference between the code that uniquely identifies a security for…
NYSE listing standards are the quantitative and governance bars a company must clear before its stock can trade on the…
Nasdaq listing tiers divide the exchange into three levels: the Global Select Market, the Global Market, and the…
The Nasdaq Global Select Market is the highest of Nasdaq's three market tiers, reserved for companies that clear the…
The Nasdaq Global Market is the middle of Nasdaq's three tiers, sitting between the elite Global Select Market and the…
The Nasdaq Capital Market is the entry tier of Nasdaq's three market levels, designed for smaller companies that meet…
NYSE American listing standards are the rules for the NYSE group's small-cap venue, the exchange most investors still…
NYSE Arca ETF listing is the process by which exchange-traded funds get approved to trade on NYSE Arca, the leading US…
OTC Bulletin Board history runs from a quotation system that FINRA launched in 1990 to its final shutdown in 2021. The…
OTC Markets pink sheets tiers are the graded levels that organize stocks trading off the major exchanges. OTC Markets…
The OTC Expert Market is the most restricted quoting venue operated by OTC Markets Group, holding securities that…
Pink Current Information is the disclosure tier within the OTC Markets Pink marketplace where an issuer publishes…
The LSE Main Market is the senior listing venue of the London Stock Exchange, home to large, established companies and…
LSE AIM is the London Stock Exchange's growth market for smaller and younger companies, governed by a lighter rulebook…
The HKEX Main Board is the senior equity market of Hong Kong Exchanges and Clearing, designed for established companies…
HKEX GEM is the Growth Enterprise Market of Hong Kong Exchanges and Clearing, a board for smaller and emerging…
The ASX listing rules are the admission and ongoing conduct standards a company must meet to have its shares quoted on…
The TSX TSXV listing tiers are the graded levels companies occupy across Canada's two main equity markets. The senior…
A Euronext Paris listing places a company's shares on one of three market segments in France, each with a different bar…
A Euronext Amsterdam listing admits a company's shares to the Dutch arm of the Euronext group, under EU rules and the…
High-frequency trading (HFT) firms compete on how quickly they can observe market data and submit orders. A few…
Spoofing is the practice of placing orders with the intent to cancel before execution, in order to mislead other market…
Quote stuffing is the practice of submitting and rapidly cancelling a very large number of orders in a short time, with…
Payment for order flow (PFOF) is the arrangement in which a retail broker routes its customers' orders to an…
A limit order book is the live ledger of unfilled buy and sell orders sitting at every price on a venue. Its…
Time and price priority is the rulebook that decides which resting order at a given price gets filled first when a…
An iceberg order is a limit order where only a small displayed slice is visible on the book at any time. The rest of…
A midpoint peg order is a non-displayed order that automatically prices itself at the midpoint of the National Best Bid…
A hidden order is a fully non-displayed limit order: nothing about it appears on the public quote, no displayed size,…
Queue position modeling estimates the probability that a resting limit order will fill before it has to be cancelled or…
Latency arbitrage is a class of trading strategies that profits by reacting to a price-relevant event a few…
Co-location is the service that lets a trading firm rent rack space inside or directly adjacent to an exchange's…
The SEC Tick Size Pilot was a two-year experiment that widened the minimum quoting and trading increment for about…
On April 9, 2001, US equity markets completed a phased move from fractional pricing (sixteenths and eighths) to decimal…
Pegged order types do not hold a fixed price. Instead they reprice automatically as the National Best Bid and Offer…
A midpoint peg order is a non-displayed order priced at the exact midpoint between the National Best Bid and Offer. It…
A primary peg order tracks the near side of the National Best Bid and Offer, anchoring a buy to the bid and a sell to…
A market peg order tracks the far side of the National Best Bid and Offer, anchoring a buy to the offer and a sell to…
A hidden order is a fully non-displayed limit order that rests in an exchange's book without appearing in the visible…
An iceberg order displays only a small visible slice of its total size while keeping the bulk hidden, then refreshes…
A reserve order is an order that splits its total size into a small displayed amount and a larger non-displayed…
A discretionary order is a limit order that shows the market one price but quietly holds permission to trade at a…
The NYSE d-quote, formally a Discretionary Order or D Order, is a tool only a floor broker can use to enter and adjust…
The IEX discretionary peg D-Peg is a non-displayed order that rests just outside the best quote and steps in toward the…
The IEX crumbling quote signal is a predictive model that flags the moments just before the national best bid or offer…
NYSE Arca is a fully electronic US stock exchange and the leading venue for listing and trading exchange-traded…
Nasdaq order routing is the set of rules that decides whether your order rests on the Nasdaq book, sweeps other…
The Nasdaq cross is the auction that sets a single official price for a stock at the open and again at the close.…
A Nasdaq imbalance only order is a special limit order built to feed the opening or closing cross by offsetting…
The NYSE opening imbalance is the published gap between buy and sell interest in a stock before the 9:30 a.m. opening…
The NYSE closing auction sets the single official closing price for every NYSE-listed stock and is the busiest moment…
The Nasdaq closing cross is a single-price auction that runs at 4:00 p.m. Eastern to set the official closing price for…
Cboe BZX is one of four U.S. equities exchanges operated by Cboe Global Markets, and it runs a price-time, maker-taker…
Cboe BYX is one of four U.S. equities exchanges run by Cboe Global Markets, and it is best known as an inverted venue.…
Cboe EDGX is one of four U.S. equities exchanges operated by Cboe Global Markets, and it runs a maker-taker model known…
Cboe EDGA is one of four U.S. equities exchanges run by Cboe Global Markets. For most of its life it was an inverted…
MEMX, the Members Exchange, is a U.S. stock exchange built and owned by the firms that trade on it. It launched to push…
The Long-Term Stock Exchange, or LTSE, is a U.S. national securities exchange built around one idea: rewarding…
Cboe EDGX Options is a U.S. options exchange that uses a customer-priority, pro-rata allocation model rather than the…
Cboe BZX Options is a U.S. options exchange that runs a pure price-time priority, maker-taker model. It fills the…
MIAX Emerald is a U.S. options exchange that uses a pro-rata allocation model and a maker-taker fee structure. It is…
ATS dark pool types describe the main categories of off-exchange venues where shares trade away from public exchanges.…
Form ATS-N is the public disclosure that every NMS stock alternative trading system must file under Regulation ATS. It…
A securities information processor SIP is the system that collects quotes and trades from every US stock venue and…
Exchange direct data feeds deliver market data straight from a single exchange, faster and in more detail than the…
The UTP quote data plan governs the consolidated feed for Nasdaq-listed stocks, the counterpart to the system that…
The CTS CQS consolidated tape carries trade and quote data for NYSE-listed and other exchange-listed stocks, the…
The OATS order audit trail system was FINRA's tool for tracking the life of an order across US equity markets, and it…
The consolidated audit trail CAT is the SEC-mandated system that records every order, cancellation, modification, and…
Long-Term Stock Exchange listing pairs ordinary financial requirements with a distinctive set of governance commitments…
The JPX Prime Market is the top-tier segment of the Tokyo Stock Exchange, created in the April 2022 restructuring for…
JPX Standard & Growth are the two non-flagship segments of the Tokyo Stock Exchange, created in the April 2022…
The SGX Mainboard is the senior listing tier of the Singapore Exchange, reserved for companies that meet defined…
SGX Catalist is the Singapore Exchange's sponsor-supervised board for fast-growing smaller companies, with no general…
The Deutsche Borse Prime Standard is the highest-transparency listing segment of the Frankfurt Stock Exchange. It…
Stock Connect is a cross-border trading link that lets investors in Hong Kong buy mainland Chinese shares, and mainland…
The LCH clearing house is one of the world's largest clearing houses, sitting in the middle of derivatives and…