Assuming the instos incur some sort of transaction costs, if not...

Assuming the instos incur some sort of transaction costs, if not just time, I simply can't see how doing so many small trades would ever be viable. Especially if they are making dozens (if not hundreds) per day.

I get what you're saying about needing to track indices and client requests etc, but honestly I can't imagine that those orders would be executed in such an inefficient manner. Over time, the excess transaction costs (time and otherwise) would be difficult to justify or recoup (IMHO).

Consequently, I am led to conclude that these small trades must serve some greater purpose.