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Key Takeaways
- FINRA is a private self-regulatory organization operating under SEC oversight.
- Its member rules cover broker conduct, supervision, margin and reporting.
- BrokerCheck provides firm and representative registration and disciplinary records.
- Regulation T sets the initial requirement when you buy, and FINRA’s maintenance floor governs the position from then on.
- The worked position has $4,000 equity after a 30% drop: $500 above a 25% maintenance floor and $900 below a 35% house requirement.
- The 2026 intraday-margin framework has an implementation period through October 20, 2027.
What is the Financial Industry Regulatory Authority (FINRA)?
The Financial Industry Regulatory Authority, or FINRA, is a private self-regulatory organization operating under SEC supervision. It regulates its member broker-dealers through rules, examinations, supervision and enforcement, and those rules cover broker conduct, margin and reporting.
FINRA administers registration systems and qualification examinations, operates BrokerCheck and provides a dispute-resolution forum. It also performs surveillance and enforcement work under agreements with securities exchanges.
Margin example: Regulation T initial and FINRA maintenance
A trader opens a margin account and buys $20,000 of a marginable stock. Regulation T lets the broker lend up to 50 percent of the purchase price, and FINRA Rule 4210 governs the maintenance level after the trade.
- Initial equity required under Regulation T: $20,000 × 50% = $10,000
- Margin loan extended by the broker: $20,000 − $10,000 = $10,000
- FINRA minimum maintenance equity at purchase: $20,000 × 25% = $5,000
- Stock falls 30 percent: position value $14,000, equity $14,000 − $10,000 = $4,000
- Maintenance check: $14,000 × 25% = $3,500 required, so equity of $4,000 still clears the FINRA minimum
After the decline, $4,000 equity exceeds the 25% maintenance requirement by $500. Under the 35% house requirement, the same account is $900 short and faces a house maintenance call.
After a 30% stock-price decline, market value is $14,000. Subtract the unchanged $10,000 loan to get $4,000 account equity.
At 25% maintenance, required equity is $3,500 and the account has a $500 surplus. At a 35% house requirement, required equity is $4,900 and the account has a $900 deficit. Plan around the broker’s house number, since that is the requirement that triggers the call.
FINRA intraday margin requirements and the pattern day trader rule
FINRA’s 2026 intraday-margin amendments took effect June 4, 2026, with firm implementation permitted through October 20, 2027. The new framework replaces the legacy pattern-day-trader designation and associated $25,000 minimum with exposure-based intraday requirements.
Use the framework your broker has implemented, together with its house requirements, when calculating account capacity for the next trade. Measure the options trade against that capacity in the options profit calculator, which shows its entry cost and maximum loss at each quantity, and confirm the structure fits the broker’s strategy approvals.
BrokerCheck, market data and FINRA rule changes
Look up any firm or representative in BrokerCheck before you open an account. FINRA’s conduct rules cover best execution and supervision, and its reporting facilities publish off-exchange equity data and member short-interest figures.
Rule changes are filed with the SEC. Some follow the approval process; qualifying categories take effect upon filing. The published rule and implementation notice identify the dates that govern the account.
Limitations of FINRA rules and data
- Check the broker’s house requirement first. FINRA requirements are minimums, and the worked 35% house requirement turns a $500 surplus under the 25% floor into a $900 deficit.
- Check the exchange’s own rules for options questions. Options exchanges are their own self-regulatory organizations, and FINRA’s role there runs through regulatory agreements.
- Use BrokerCheck for registration, employment and disciplinary records, and the firm’s fee schedule and execution reports for its costs and execution quality.
- Confirm which day-trading framework your broker runs. Firms may implement the intraday-margin framework through October 20, 2027, so two brokers can apply different rules during that period.
- Read off-exchange volume and short interest together with exchange volume. Each report covers one slice of a stock’s trading and positioning.
Bottom line
FINRA writes and enforces rules for U.S. member broker-dealers under SEC oversight, from conduct and margin to trade reporting. Use BrokerCheck to review a firm, follow the margin and intraday framework your broker has actually implemented, and plan account capacity around its house requirements rather than the FINRA minimum alone.
Clear answers
Frequently Asked Questions
Sources and Further Reading
- FINRA: What We Do
- FINRA Regulatory Notice 26-10: Intraday Margin Requirements
- FINRA: Margin Regulation Key Topic
- FINRA Rule 4210: Margin Requirements
- FINRA: OTC (ATS and Non-ATS) Transparency Data
How entries are sourced, calculated and updated: editorial methodology.