Imported from previous forum
After sending a cancel request with Partial Cancel Indicator turned on (Fix ver 4.0) and receiving execution report "replaced" (39=5) will all consecutive execution repots carry the new client order ID or the original order ID? After all the purpose is not to lose the line (place in the Order Book). At the same time the changed order will have a new quantity. These two issues may and may not trigger the new order id to be reflected in the execution report. The main goal is to clarify the fix standard. My next question - is it true that partial cancels will not exist in Fix version 4.1, does it mean that everything will be handled through cancel replacements? Thanks in advance.
[ original email was from Ryan Pierce - rpierce@taltrade.com ]
> After sending a cancel request with Partial Cancel Indicator turned on (Fix ver 4.0) and receiving execution report "replaced" (39=5) will all consecutive execution repots carry the new client order ID or the original order ID? After all the purpose is not to lose the line (place in the Order Book). At the same time the changed order will have a new quantity. These two issues may and may not trigger the new order id to be reflected in the execution report. The main goal is to clarify the fix standard. My next question - is it true that partial cancels will not exist in Fix version 4.1, does it mean that everything will be handled through cancel replacements? Thanks in advance.
>
Partial cancels do not exist in FIX 4.1.
The reasoning behind this, as I understand it, is to simplify the protocol and to divorce it from specific exchange methodology.
Having two separate ways of modifying orders is quite complex. Rather than say "Do a cancel/replace" or "Do a cancel/leaves" one would say in FIX "Modify this order." The program receiving the order and routing it elsewhere should have enough intelligence to use the most optimal way available to carry out the modification, i.e. a Cancel/Leaves if routing it to SIAC and the only change was a decrease in volume, so that the order does not lose its place in the book.
Concerning IDs in FIX 4.1, the ClOrdID must change when you do a modification, but the OrderID can either change or stay the same at the option of the firm receiving the modification.