Citadel Securities has asked the SEC to reconsider its June 11 proposal to eliminate Rule 611 of Regulation NMS, the order protection rule adopted in 2005 to prevent trade-throughs, or executions at prices worse than quotes shown on another venue. In an August 17, 2026 comment letter, the firm argued the change would make it easier for brokers to bypass the best displayed exchange prices, push more orders into internalization or other private venues, and reduce incentives to post competitive quotes on public markets. Citadel said the SEC’s economic analysis was "fatally flawed" and argued projected compliance savings of about $250,000 per trading day were small relative to the potential harm to market quality. The firm warned the repeal, proposed by the SEC under Chairman Paul Atkins alongside related Rule 610(e), could reduce liquidity, weaken price discovery and leave retail investors worse off. Rather than a full repeal, Citadel urged the SEC to consider a minimum volume threshold for exchanges to qualify for protected quote status, preserving trade-through protections while limiting friction from low-volume venues.