FINRA Opens Comment Period on Best-Execution Guidance Modernization

FINRA has opened a comment period on modernizing its best-execution guidance under Rule 5310, with comments due by 25 September 2026.

The self-regulatory organization says it is reviewing the rule and related interpretive guidance as part of its FINRA Forward rule-modernization initiative. The notice points to major market-structure developments, including the SEC’s proposal to rescind the trade-through rule under Regulation NMS, as a reason to revisit how broker-dealers evaluate routing, venue access and execution quality.

FINRA is asking for feedback on displayed and non-displayed liquidity, affiliated venues, payment for order flow, internalization, odd-lot handling, locked and crossed markets, access fees, institutional order flow, extended-hours trading and the use of AI in order handling or routing decisions.

For active traders, the practical question is how broker routing standards may be judged if the regulatory backdrop changes. Best execution affects the quality of fills, price improvement, liquidity access and the way brokers disclose or manage conflicts when routing customer orders.

Why it matters

Best execution is one of the main protections behind retail and institutional order handling. Any modernization could influence broker routing reviews, execution-quality metrics and how firms document decisions across normal and extended-hours sessions.

What to watch next

The comment deadline is 25 September 2026. Traders should watch whether FINRA later proposes specific changes for internalized order flow, affiliated venues, access fees and AI-assisted routing.