On September 27, FINRA filed a proposed rule change with the SEC to: (i) update Rule 6121 (Trading Halts Due to Extraordinary Market Volatility) to reflect changes to market-wide circuit breaker triggers for National Market System stocks and (ii) amend Rule 6440 (Trading and Quotation Halt in OTC Equity Securities) to provide specifically for a halt in trading in all OTC Equity Securities when a market-wide circuit breaker is in effect for NMS stocks. SEC Release. FINRA Proposed Rule.