Anyone have enough experience with VWAP to estimate what percentage of daily volume can be traded reasonably using VWAP orders? ( no my account is not that big its just a theoretical question )
Reasonably? I suspect that even 5% of daily volume will probably cost you some slippage. I would tread carefully in illiquid stocks.
In the case of high volume stocks, I doubt you will have a problem with size, unless you are trading huge sums.