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REDDIT

SPX/CBOE experts...regarding instant auctions on spreads.

T
Feb 13, 2025 · 01:48

So our bot suddenly no longer seems to work on IBKR because "Adaptive" price algo seems to no longer work on spreads. But as I understand it the CBOE does an instant auction on spreads anyway, so even with a market order perhaps we'd always beat the true spread market price on a short spread, meaning we'd do better than: bid price on the short, less ask on protective long= net premium, in theory? We would set a limit of current market price to be safe (so I guess we're technically doing limit orders), but should we expect to do better on such market orders, let's say the majority of the time, thanks to this auction? Do all Market Makers participate or only some?

There's other ways we could go, like Snap to Mid with offset, but that would not be guaranteed trade like a Market order with that CBOE auction for combos...we assume?