Not a complete analysis, but some interesting stats. From The Lothian Letter. If you're in the industry - worth the money. Options Exchange Stats in June - Some Highlights Spencer Doar - JLN OMX PHLX, Cboe and MIAX led all exchanges in percentage of time spent at best bid/offer AND greatest size, according to Tabb's Options Liquidity Matrix, coming in at 23.3 percent, 17.5 percent and 13.4 percent, respectively. The top three ranking changes when you remove greatest size and just focus on percentage of time at best bid/offer. Then the top three are BATS BZX, NYSE Arca and Nasdaq, with 81.3 percent, 73.3 percent and 71.4 percent, respectively. The lead exchanges in terms of average contract size per trade were NYSE AMEX, OMX PHLX, and Cboe, with 25.3 contracts, 22.0 contracts and 17.2 contracts, respectively. In dollars per trade terms, the top three shifts to Cboe, NYSE AMEX and then OMX PHLX.
There is a simple answer for this. AMEX, PHLX, and Cboe-this is where the bulk of trades are crossed by floor brokers representing off floor sales trading desks. Each of these exchanges also has a COB. BATS , Arca and Nasdaq offer healthy rebates for offering liquidity so many customers and MM ofer more size on these. What would be more helpful to option customers that want to interact with other customers, is to know where most customer orders are routed by Broker dealer's smart or default routes. Where can a customer not have to rely on a MM? I'm not sure, but I would bet PHLX and CBOE might be good targets. The old owners of PHLX used to have capped deals with PHLX on monthly fees, so their order router on SMART routed orders might target there first. And, many retail brokers have deals with DMMS on the CBOE to get orders routed there. This is from July 20. Impossible for me to tell what volume is from crosses, but look at equity option volume from PHLX. 16.24% is impressive with 15 exchanges.