VWAP (volume weighted average price)

Traders time their trades until VWIP makes their trading cost appear favorable.Trader can trade at favorable bids and asks by waiting orders to be brought to the trader . In both these cases, traders might forgo profits through delay.

Can someone explain why dealer may forgo profits through delay ?

More likely a broker than a dealer.

A trader’s year-end bonus might depend on how often he beats the VWAP.