Douro Labs and the Hyperliquid Policy Center told the SEC on Aug. 17 that rescinding Regulation NMS Rules 611 and 610(e) should be paired with updated best-execution standards for tokenized stocks and other blockchain-based securities trades, while the Blockchain Association separately backed the same proposal in an Aug. 17 comment letter publicized on Aug. 18. The groups argue the SIP-based National Best Bid and Offer cannot reliably assess on-chain executions because blockchain venues run continuously, including weekends and holidays, automated market makers do not publish firm quotes, and settlement occurs at blockchain speeds rather than traditional market-data intervals. Douro Labs and Hyperliquid asked the SEC to allow independent qualifying reference prices under transparency and anti-manipulation criteria, outlining four conditions such benchmarks should meet and saying Douro Labs has already built a service designed to satisfy them. They also urged the agency to keep best-execution oversight centered at FINRA, account for blockchain-specific costs such as network fees, bridge fees and maximal extractable value, and recognize investor-set slippage controls as an alternative to fixed trade-through-style protection. The Blockchain Association said Rule 611 has increased costs, market-structure complexity, order-handling constraints, exchange proliferation and fragmentation in stock trading, and argued that revising the framework would better fit DeFi, decentralized exchanges and tokenized securities markets while aligning with the administration's stated push to strengthen U.S. leadership in cryptocurrency and financial technology. The comment period on the SEC proposal under file number S7-2026-20 closed on Aug. 17.