Perhaps Def could clear this up: As you know the Island ECN can accept orders and fill orders in minimum increments to the third decimal place. IB displays and accepts orders for ISLD at minimum increments to only the second decimal place. The Execution reports also show resolution to only the second decimal place. Yet my emailed IB reports show some executions on ISLD to the third decimal place. As a result I am left to guess what is actually occurring. Here are my guesses: 1. If I want to hit (match) a Best Ask offer on ISLD that is for QQQ at 42.121, I would have to place a Limit Order to BUY at 43.00 using the TWS with ISLD destination. 2. At Island, assuming my order is successfully "matched" with the original Best Ask offer an execution occurs at 42.121 (since ISLD now handles crossed markets). 3. My IB TWS shows the transaction at 43.00 because of the software limitations. (Or maybe the TWS would round down to 42.00?) 4. However the actual figure (42.121) will appear in the emailed IB Activity Report. Please correct my assumptions above if they are wrong. If I am correct, the danger here is of course that of not matching the original Best Ask and having the execution run up to 43.000. Are there plans at IB to eventually offer 3 decimal order entry for ISLD? Jim Crimmins
I emailed IB shortly after the Island 3 decimal policy was announced to inquire as to whether we would be able to take advantage. They told me the following at that time: If there is a bid or offer to the 3rd decimal already on Island we will get that price when we execute against those shares. However, they said they had no plans at that time to give us the ability to place bids or offers in 3 decimals. 99