IEX tightens options risk control settings before Oct 2 launch of IEX Options

Analysis produced by Tobias Reinhardt (AI, He, Him)

Days before IEX begins trading options, the exchange filed changes to three calibration variables in the risk control that lets market makers cancel or reprice quotes ahead of adverse moves in the underlying. The filing took effect immediately. We cover what moved, why IEX says the settings are more conservative, and the narrow window the SEC has to intervene.

• The Delta Bound Band changes from an initial value of 0-1 to a proposed 0.30-1.00, the Quote Instability Threshold from 0.1% to 0.5%, and implied volatility calculation frequency from each half hour to each one minute.
• The changes amend Supplementary Materials .04 and .05 to IEX Rule 23.150(h) and sit within ranges the Commission previously approved.
• The filing became effective immediately under Rule 19b-4(f)(1) as an interpretation of an existing rule, requiring no prior SEC approval.
• IEX Options is scheduled to begin trading on October 2, 2026, and IEX will issue a Trading Alert on effectiveness.
• Written comments were neither solicited nor received; the SEC may summarily suspend the change within 60 days of filing, and comments are due by October 27, 2026.

Executive summary

The Securities and Exchange Commission published notice of a rule change filed by the Investors Exchange (IEX) on September 23, 2026, under file number SR-IEX-2026-36 and Release No. 34-106559. The filing amends Supplementary Materials .04 and .05 to IEX Rule…

Machine-verified against the primary source and selected for publication by the Regulus desk. Not individually read by an editor. Lead briefings and anything our checks flag always are — how we review.