Principal Transactions: Markups, Disclosure, and Best Execution

A principal transaction by a broker-dealer is a trade in which the firm itself is the counterparty: it sells you securities out of its own inventory when you buy, or buys your securities into inventory when you sell, instead of routing your order to another buyer or seller. Because the firm’s own money is on the other side of the trade, it profits from the price rather than from a commission, and federal and FINRA rules require it to disclose that role, price the trade fairly, and still work to get you the best reasonably available execution.

How a Principal Trade Works

A broker-dealer acting in a principal capacity keeps an inventory of stocks, bonds, or other instruments bought with its own capital. When your buy order arrives, the firm can fill it straight from that inventory. When you sell, it takes the security onto its books. The trade settles internally, which can mean faster execution than an order routed to an exchange.¹

The incentive structure is what makes principal trades different. A broker acting as your agent earns a flat commission no matter what price you get. A broker acting as principal earns the spread between what it paid for the security and what it charges you. That is why regulators layer extra disclosure and fairness requirements on top of principal trading.

Where You’ll Most Often See Principal Trading

Most stock orders on major exchanges are handled on an agency basis, with competing exchanges and market makers driving execution costs down. Principal trading dominates in the bond market. Corporate bonds, municipal bonds, and government debt trade over the counter, and dealers provide liquidity by standing ready to buy or sell from their own inventory because there is rarely a continuous stream of matching orders.

That distinction has a direct effect on your costs. Buying 100 shares of a heavily traded stock costs pennies in execution. Buying a corporate bond usually means dealing with a single dealer who sets the price and folds compensation into it.

Markups and Markdowns

Principal trades do not carry a separate commission line. The firm’s compensation is baked into the price. When it sells to you, it adds a markup above the prevailing market price. When it buys from you, it subtracts a markdown. You see one net number.

The bid-ask spread on a quote is the visible version of this. The bid is what the dealer will pay to buy from you; the ask is what the dealer will charge to sell to you. The gap covers the dealer’s inventory risk, operational costs, and profit. In thinner markets, such as small-issue municipal bonds, the spread widens because the dealer has more trouble offloading the position.

How the Prevailing Market Price Is Set

To measure whether a markup is fair, you need a baseline. For a standard principal trade from existing inventory, the benchmark is the prevailing market price at the time of the transaction, and in the absence of better evidence the firm’s own recent cost of acquiring the security is the best indicator.² If a dealer paid $98 for a bond and sells it to you at $99.50, the $1.50 gap is the markup that gets tested.

Riskless Principal Trades

Not every principal trade comes from long-held inventory. In a riskless principal transaction, the dealer already has your order in hand, goes out and buys the security from the market, then immediately resells it to you. It briefly owns the security on paper but never really carries the risk of holding it.³ For riskless trades, the baseline for measuring the markup is the dealer’s purchase price in the offsetting trade that same day.

FINRA requires firms executing these net-basis transactions to get your consent first. For retail customers, that consent must be in writing on an order-by-order basis. Institutional customers can provide blanket consent through a negative-consent letter or an oral agreement, provided they have a meaningful chance to object.⁴

What Your Trade Confirmation Must Show

Federal rules require your broker-dealer to send a written trade confirmation at or before settlement. It must state whether the firm acted as principal or as an agent, and if principal, whether the firm is a market maker in that security. It must also include the date, time, price, and quantity.¹

For exchange-traded stocks where the firm acts as principal, the confirmation must show the reported trade price, the price you actually paid, and the difference. That difference is your markup. For riskless principal equity trades, the confirmation must disclose the gap between the dealer’s purchase price and your price.¹

Extra Disclosure on Bond Trades

Bond confirmations historically showed only a net price. That changed in 2018 when FINRA Rule 2232 took effect. For corporate and agency debt securities, if the dealer executed an offsetting principal trade on the same day in a size equal to or larger than your order, the confirmation must show the markup as both a dollar amount and a percentage of the prevailing market price.⁵ The confirmation must also state execution time down to the second and provide a link to pricing data for the specific security.⁶

Reading a Confirmation in Practice

Look for the word “principal” or “agent” on every confirmation. If it says principal, you were not charged a commission; the firm’s compensation is embedded in the price. For stock trades, the markup should be broken out. For bond trades, check whether a markup dollar amount and percentage appear, and compare that percentage against the fairness factors below. If the capacity field is missing or unclear, call your broker.

Fair Pricing Standards

FINRA Rule 2121 requires every principal transaction to be priced fairly, taking all relevant circumstances into account. The rule’s supplementary material includes the well-known “5% Policy,” which is a guideline, not a ceiling. A markup below 5% can still be unfair, and a markup above 5% can sometimes be justified.²

Regulators weigh several factors together when judging fairness:

Type of security. Stocks typically carry lower markups than bonds, and bonds lower than limited-partnership interests or other complex products.
Availability. A thinly traded security that takes work to locate warrants a wider spread than one with dozens of active dealers.
Price of the security. Lower-priced securities often carry higher percentage markups because the dollar amounts are small and handling costs are proportionally larger.
Transaction size. A small-dollar trade may justify a higher percentage markup to cover fixed operational costs.
Prior disclosure. Telling you about the markup before the trade counts in the firm’s favor, but disclosure alone cannot justify an excessive charge.
Pattern of markups. Regulators look at overall pricing behavior, not just individual trades.
Nature of the business. A full-service firm providing research and advisory support may justify a different markup than an execution-only dealer.

Violations can bring fines, mandatory restitution, and suspension of trading privileges. FINRA reviews trading patterns and compares a firm’s prices against the prevailing market at the exact moment of each transaction.²

Best Execution

Fair pricing and best execution are separate obligations. A markup can sit within the 5% guideline and still fail the firm’s duty to get you the best reasonably available price. FINRA Rule 5310 requires broker-dealers to use reasonable diligence to find the best market and execute at the most favorable price possible under current conditions, and that duty applies to principal trades.⁷

Reasonable diligence turns on the character of the market for the security (price, volatility, liquidity), the size of your order, the number of alternative markets the firm checked, and the specific terms of your order. Firms that fill customer orders internally rather than routing them to competing dealers must conduct rigorous quarterly reviews of their execution quality, comparing their fills against competing markets on price improvement, speed, and transaction costs.⁷

Firms are also barred from inserting an unnecessary middleman between themselves and the best available market. Routing your order through an affiliate to generate extra compensation, rather than going directly to the market with the best price, violates the rule’s ban on interpositioning.

Regulation Best Interest and Conflicts of Interest

When a broker-dealer recommends a security it happens to hold in inventory, the conflict is obvious: the firm benefits from unloading the position to you. The SEC’s Regulation Best Interest, which took effect in 2020, addresses this directly. Under the rule’s conflict-of-interest obligation, firms must establish policies to identify and mitigate conflicts arising from principal trading and proprietary product recommendations.⁸

The rule does not prohibit principal transactions. It requires the firm to act in your best interest at the time of the recommendation, consider reasonably available alternatives, and put supervisory procedures in place that specifically monitor principal-capacity and higher-compensating recommendations. A firm that limits its recommendations to proprietary products must disclose that material limitation and take extra steps to mitigate the resulting conflict.⁸

When Your Investment Adviser Is the Counterparty

The rules tighten when the firm is both your investment adviser and the other side of your trade. Section 206(3) of the Investment Advisers Act makes it unlawful for an adviser to buy from or sell to a client while acting as principal without first disclosing that role in writing and obtaining the client’s consent.⁹

The disclosure must go beyond noting that the adviser is acting as principal. It has to include enough detail, including the current quoted price, best-price information, and any applicable charges, for you to evaluate the conflict. If the adviser obtains your consent after execution but before settlement, the disclosure must cover the final pricing and commission details so you can make an informed decision. You are under no obligation to approve the trade, and the consent process cannot be structured to pressure you into agreeing.⁹

If your adviser has discretionary authority over your account, the potential for abuse is greater because the adviser could execute principal trades without asking you each time. The combination of fiduciary duty and transaction-by-transaction consent under Section 206(3) is designed to prevent that.

Protecting Yourself in Principal Trades

The regulatory framework works best when you engage with it. A few habits help. Read every trade confirmation. The capacity line tells you whether the firm was on the other side, and the markup disclosure tells you what you paid. Compare bond prices against FINRA’s TRACE data, which reports transaction prices for corporate and agency bonds; if the price on your confirmation is meaningfully worse than recent TRACE prints, ask questions.

Pay special attention to markups on less liquid securities. A 1% markup on an actively traded Treasury bond would be unusual; the same percentage on an obscure municipal bond might be reasonable given search costs and inventory risk. Context matters more than any single percentage threshold. And remember that “no commission” does not mean “no cost.” Firms advertising commission-free bond trading are almost certainly earning their revenue through markups. The cost is real; it is just less visible.

1
eCFR. 17 CFR 240.10b-10 – Confirmation of Transactions
2
FINRA. FINRA Rule 2121 – Fair Prices and Commissions
3
U.S. Securities and Exchange Commission. Investor Bulletin – How to Read Confirmation Statements
4
FINRA. FINRA Rule 2124 – Net Transactions with Customers
5
FINRA. FINRA Rule 2232 – Customer Confirmations
6
FINRA. Fixed Income Confirmation Disclosure – Frequently Asked Questions
7
FINRA. FINRA Rule 5310 – Best Execution and Interpositioning
8
U.S. Securities and Exchange Commission. Regulation Best Interest
9
U.S. Securities and Exchange Commission. Interpretation of Section 206(3) of the Investment Advisers Act of 1940