Payment for Order Flow: How Free Brokers Make Money

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You open a brokerage app in the elevator between floors, tap a purchase, and see a commission of zero. It is natural to wonder how the firm stays in business. One of the main answers is payment for order flow, often shortened to PFOF: a broker routes your order to a large trading firm, and that firm pays the broker a small amount for the privilege of executing it. The practice is legal and disclosed, it is also debated, and what matters to you is whether the execution you receive is good, which you can check.

Key Takeaways

• Payment for order flow is compensation a broker receives from a market maker or wholesaler for sending customer orders to it.
• A commission of zero does not mean the trade costs nothing, because the bid-ask spread and execution quality still determine your real price.
• Brokers owe customers a duty of best execution, and they publish quarterly routing reports that show where orders go.
• Price improvement, meaning an execution better than the displayed quote, is one of the measurable things to look for.
• Your own order type and the liquidity of the stock often matter more than the routing arrangement.

What is payment for order flow?

When you place a stock order, your broker decides where it will be executed. It might send the order to a public exchange, to an alternative trading system, or to a wholesale market maker. In a PFOF arrangement, the wholesaler pays the broker a small amount per share or per order in return for the flow of customer orders.

The wholesaler is willing to pay because retail orders are valuable to it. They are usually small and are unlikely to be placed by someone with privileged information, which makes them easier to trade against profitably. The wholesaler earns the bid-ask spread and shares part of that economics with the broker.

How can a broker charge zero commission?

A broker has several revenue streams, and PFOF is one of them. Others include interest earned on customer cash balances, fees from lending out securities held in margin accounts, subscription tiers, and interest on margin loans. A firm that relies on order routing revenue can afford to drop commissions because the revenue arrives from the other side of the trade.

That is not inherently sinister. It is a cross-subsidy, and it has made investing cheaper to start. The point worth holding onto is that the cost moved. It shifted from a visible line item on your statement to the quality of your execution, which is harder to see unless you look for it.

What does best execution actually require?

Brokers have a regulatory obligation to seek the best reasonably available terms for customer orders, considering price, speed, likelihood of execution, and other factors. FINRA and the SEC oversee this duty. The obligation is on the broker, and a payment from a wholesaler does not remove it. Firms are expected to review their routing regularly and compare venues, not simply send everything to the highest bidder.

To make this checkable, brokers publish quarterly reports on order routing under SEC rules. The reports show which firms receive customer orders and, for each, whether the broker receives payment and how much. Investor.gov explains these disclosures in plain language, and the reports themselves are public.

What does an average investor actually experience?

The measurable effect is usually tiny per trade. For a liquid, widely held stock the spread is a cent or so, and price improvement can bring the execution slightly inside the displayed quote. The harder cases are thinly traded companies, fast markets, and large orders, where the routing choice and your order type can matter more.

Critics argue that the arrangement creates a conflict of interest, since the broker is paid by the party that trades against its customers. Defenders say that the competition among wholesalers delivers price improvement and that retail costs have fallen. Both positions are held by serious people, and regulators have reviewed the practice repeatedly. You do not have to settle the debate to protect yourself. You need to look at your own results.

What does a week of checking this look like? (An illustrative example)

This is a hypothetical example, not a record of results. Imagine an executive who places a few orders a month. On the first weekend of a quarter she downloads her broker's routing report and reads the section on the largest venues and any payments disclosed. She notes the average price improvement figures the broker reports, if any.

Then she compares that report with two of her own recent fills, looking at the price at the moment of the order and the price she received. She finds one fill inside the quote and one slightly outside it, in a thinly traded name during a busy open. She decides that for that kind of stock she will use limit orders. The exercise takes less than an hour a quarter and replaces a vague worry with a specific habit.

Frequently Asked Questions

Is payment for order flow legal?

Yes. It is permitted in the United States, provided brokers disclose it and continue to meet their best-execution obligations. Some other jurisdictions have restricted or banned it, so the rules depend on where your account is held.

Does zero commission mean I pay nothing to trade?

No. You still pay the bid-ask spread, and execution quality determines whether you receive a price at, inside, or outside the displayed quote. Other costs, such as margin interest or account fees, may also apply depending on how you use the account.

How do I find out where my broker sends orders?

Brokers are required to publish routing reports, typically quarterly, naming the venues that receive customer orders and describing any payments received. They are usually on the broker's website. Investor.gov and FINRA offer plain-language guides to reading them.

Can I avoid payment for order flow?

Some brokers do not accept it and say so in their disclosures, usually in exchange for charging commissions or other fees. Whether that is better for you depends on how often you trade and the stocks you hold, so compare total cost rather than only the headline commission.

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