Market makers are registered firms that stand ready to buy and sell specific securities throughout the trading day, quoting a price to buy (the bid) and a price to sell (the ask) at the same time. They earn the small gap between those two prices and, in exchange, absorb the risk of holding inventory so that other investors can trade almost instantly. If you have ever wondered who the market makers are behind a retail brokerage app or a stock exchange, they are the entities on the other side of the screen making sure a buyer exists when you sell and a seller exists when you buy.
The role used to belong to specialists on physical exchange floors. Today it belongs mostly to firms running algorithms that reprice thousands of quotes per second, plus a smaller set of human trading desks handling instruments that don’t fit an algorithm well.
What Market Makers Actually Do
Liquidity is what lets you sell a stock in a second at a price close to the last trade. Market makers create that liquidity by continuously posting prices they will honor. When you send a market order, it doesn’t sit waiting for a matching investor to appear. A market maker fills it, often in milliseconds.
This matters most when markets are under stress. When bad news hits and everyone wants to sell the same stock, market makers absorb that selling by buying shares into their own inventory. They take a real financial risk doing it, but their presence prevents the kind of price gaps that would make ordinary investing feel like gambling. The payoff for the market as a whole is tighter spreads, faster fills, and confidence that you can exit a position when you need to.
The Main Types of Market Makers
Designated Market Makers on the NYSE
On the New York Stock Exchange, Designated Market Makers are assigned to specific listed companies and carry formal obligations to keep trading orderly in those names. DMMs post quotes in the exchange’s order book and commit capital during the opening and closing auctions, the highest-volume moments of the day. Human judgment still matters at the open, where overnight news creates pricing uncertainty and the DMM helps establish a fair opening price.1NYSE. Designated Market Makers (DMMs) Improving Liquidity and Market Quality
Electronic Market Makers and Wholesalers
Firms like Citadel Securities and Virtu Financial dominate modern equity market making through high-frequency algorithms that adjust prices in microseconds. They operate on exchanges and also off-exchange as “wholesalers,” executing retail orders that brokerages route directly to them rather than sending to a public exchange. Wholesalers fill those orders at prices inside the national best bid and offer, which gives retail investors a small amount of price improvement compared with the displayed exchange price. That model gives these firms access to a large share of retail trading volume.
Investment Banks
Large institutions such as Goldman Sachs and Morgan Stanley make markets through internal trading desks, usually in instruments that are harder to trade electronically. Corporate bonds, options, and foreign currencies often require human negotiation and larger capital commitments than equities. Where electronic firms focus on speed and volume in stocks, investment banks tend to handle bigger, more specialized institutional orders where the spread is wider and the holding period longer.
How Market Makers Make Money
The Bid-Ask Spread
The core revenue source is the spread. If a firm bids $50.00 for a stock and offers to sell at $50.02, that two-cent gap is the gross profit on a round trip. Across millions of shares a day, a penny captured thousands of times becomes serious money. The risk is real, though. If a market maker buys at $50.00 and the price drops to $49.95 before it can sell, it eats the loss. Software adjusts quotes in real time to keep net exposure low, and high volume smooths out individual losing trades.
Exchange Rebates
Exchanges also pay market makers for posting quotes that add liquidity to the order book. Under the “maker-taker” model, a firm that posts a resting order receives a small rebate when that order is filled, while the firm that removes liquidity pays a fee. On the Investors Exchange, displayed liquidity rebates run up to $0.0023 per share for firms adding at least 40 million shares of displayed liquidity a day.2Securities and Exchange Commission. Notice of Filing and Immediate Effectiveness of Proposed Rule Change to Amend the Exchange Fee Schedule Concerning Equities Transaction Pricing Small per share, meaningful at scale.
Registration and Capital Requirements
Becoming a market maker isn’t something a firm can decide to do one morning. It has to register as a broker-dealer through FINRA and register separately on each exchange where it intends to make markets.3FINRA.org. FINRA Applicant Firm Checklist
The SEC’s Net Capital Rule then imposes ongoing financial requirements. A broker-dealer making a market must hold net capital of at least $2,500 for each security in which it makes a market, measured on the average number of markets made over the preceding 30 days. For securities priced at $5 or below, the minimum drops to $1,000 per security. The per-security calculation is capped at $1,000,000, though the rule’s general minimums for broker-dealers may require more depending on the firm’s other activities.4eCFR. 17 CFR 240.15c3-1 – Net Capital Requirements for Brokers or Dealers Not trivial sums when a firm is quoting hundreds of names at once.
The Rules Market Makers Have to Follow
Continuous Two-Sided Quotes
Both Nasdaq and FINRA require registered market makers to maintain a continuous two-sided trading interest during regular market hours. That means posting both a bid and an offer for every security in which the firm is registered, and replenishing those quotes after each execution.5Nasdaq. Nasdaq Equity 2 Market Participants – Section 5 Market Maker Obligations FINRA Rule 6272 imposes the same requirement for ADF-eligible securities.6FINRA.org. FINRA Rule 6272 Character of Quotations
The obligation is suspended during formal trading halts, pauses, and suspensions, and doesn’t resume until after the first regular transaction on the primary listing market following the halt.5Nasdaq. Nasdaq Equity 2 Market Participants – Section 5 Market Maker Obligations Market makers aren’t required to quote into a halt, but they are expected to stay in the market during ordinary volatility that doesn’t trigger a formal pause.
Quote Width and Size
A market maker can’t satisfy the obligation by posting absurdly wide quotes. FINRA sets maximum percentages for how far a bid or offer can sit from the national best bid or offer. For stocks in the S&P 500 or Russell 1000, the initial quote must be within 8% of the NBBO during core hours, widened to 20% during the first and last minutes of trading. For other stocks priced at $1 or above, the limit is 28%.6FINRA.org. FINRA Rule 6272 Character of Quotations On Nasdaq, each quote must display at least one standard round lot of shares.5Nasdaq. Nasdaq Equity 2 Market Participants – Section 5 Market Maker Obligations
Penalties
Failing to meet these obligations can bring censure, fines, suspension, or revocation of market maker registration.5Nasdaq. Nasdaq Equity 2 Market Participants – Section 5 Market Maker Obligations FINRA’s sanction guidelines give a sense of scale. For quality-of-markets violations such as best-execution failures, small firms face fines of $10,000 to $310,000, while midsize and large firms face fines starting at $50,000 with no stated upper limit. Fines for trading ahead of customer orders run from $5,000 to $310,000.7FINRA.org. FINRA Sanction Guidelines
The Short Sale Exemption
Market makers get a narrow but significant exception to the normal rules on short selling. Under Regulation SHO, anyone selling a stock short must first locate shares to borrow. Market makers engaged in bona fide market making are exempt from that locate requirement because they need to sell shares they don’t currently own in order to fill incoming buy orders.8eCFR. 17 CFR Part 242 – Regulation SHO Regulation of Short Sales
The exception is deliberately narrow. It doesn’t cover speculative short selling disguised as market making, trading patterns disproportionate to the firm’s normal activity, or arrangements where a market maker lends its exemption to a party trying to dodge the locate rule.9U.S. Securities & Exchange Commission. Key Points About Regulation SHO Close-out obligations still apply. If a trade results in a failure to deliver, the market maker must close out the position by the beginning of trading on the third settlement day after the settlement date. If it doesn’t, the firm can’t make any new short sales in that security until the position is resolved.10U.S. Securities & Exchange Commission. Division of Trading and Markets Guidance Regarding Rules to Protect Investors Against Naked Short Selling Abuses
Volatility Pauses
The Limit Up-Limit Down plan is the main mechanism for stopping runaway price moves in individual stocks. When one side of a stock’s national best quote hits the edge of a pre-set price band, the stock enters a “Limit State.” Market makers and other participants can then supply liquidity to pull the price back within bounds. If the price doesn’t recover within 15 seconds, the primary listing exchange declares a five-minute trading pause across all markets trading that security.11SEC.gov. Limit Up-Limit Down Pilot Plan and Associated Events During the pause, the two-sided quote obligation is suspended, and trading reopens with an auction similar to the morning open.
How Market Makers Handle Retail Orders
When you place a stock order through a retail brokerage, your order likely goes not to an exchange but to a wholesale market maker that pays your broker for the right to execute it. This is payment for order flow. The wholesaler fills your order at a price slightly better than the exchange quote and keeps the rest of the spread. Your broker gets paid for the routing, which is one reason many brokerages charge zero commissions. Payment for order flow remains legal; the SEC formally withdrew a proposed Order Competition Rule that would have required retail orders to run through exchange-based auctions in June 2025.12U.S. Securities and Exchange Commission. Order Competition Rule
Existing Regulation NMS rules still require meaningful disclosure. Rule 605 requires market centers to publish monthly reports on execution quality, including fill speeds and price improvement. Starting in November 2026, updated Rule 605 requires these reports to calculate price improvement relative to the best available displayed price, making it easier to compare venues.13SEC.gov. Extension of Compliance Date for Disclosure of Order Execution Information Rule 606 separately requires brokers to disclose where they route orders and any payments they receive for doing so.14eCFR. 17 CFR Part 242 – Regulation NMS Regulation of the National Market System
A Note on Crypto Market Makers
Firms providing liquidity on crypto trading platforms sit in a different regulatory place. As of February 2026, the SEC’s Division of Trading and Markets has issued guidance indicating that platforms trading crypto asset securities must comply with Regulation ATS. For broker-dealers holding stablecoin positions, the SEC staff will not object to applying a 2% haircut of market value when calculating net capital, rather than treating the position as having no ready market.15U.S. Securities and Exchange Commission. Division of Trading and Markets Frequently Asked Questions Relating to Crypto Asset Activities and Distributed Ledger Technology In practice, many crypto market makers operate outside the traditional broker-dealer framework, especially for tokens the SEC hasn’t classified as securities. Fewer enforceable obligations around continuous quoting, capital adequacy, and fair execution apply there than in equities, which is one of the real differences between trading stocks and trading crypto.