Nasdaq ISE gives options desks more room on trade ratios

Options traders now have another place to send multi-leg trades that did not fit Nasdaq ISE’s old size test. The exchange says its immediately effective filing lets those orders use both matching and mismatching leg ratios on the Complex Order Book and in certain auctions.

That matters when traders are trying to package several linked options into one strategy, not just buy or sell a single contract. If the order can be accepted in more ratio shapes, it can be easier to match the trade the trader actually wants to place.

The ratio test got wider

Nasdaq ISE defines a conforming ratio as one that falls between one-to-three and three-to-one. Anything outside that band is non-conforming. The exchange also says stock-option and stock-complex strategies can use larger ratios tied to the stock leg, which gives traders more room to structure hedges and other multi-leg strategies.

The change applies both on the Complex Order Book and in various auctions, so the order has more than one path to execution. That is the main point of the filing: not a new market altogether, but a looser fit for trades that were already being built.

More room, with guardrails

The new flexibility does not erase the market rules around it. Non-conforming complex orders still cannot jump ahead of priority customer orders on the single-leg book, where one-contract orders sit, and they cannot trade through the national best bid and offer, or NBBO, the best prices publicly available across markets.

The practical effect is more execution flexibility, not a promise of better prices or more volume. The SEC published notice of the filing on June 10, 2026, and Nasdaq ISE filed the rule change on May 29.