Patrick Rooney
Sponsor
Volume swells at the open an close because many model based traders wish to capture the opening or closing price as that is what their historical model returns are based upon. As they may model on end of day data, they try and trade these prices. The traders are often bench-marked on capturing this price. Many big orders are based on VWAP also and volume attracts volume...again traders must try to match the volume weighted average price and as most volume occurs at open and close, big chunks of VWAP orders will occur then. Bank order desks are generally flooded with Market on Close (MOC) and Market on Open (MOO) orders and it's a challenge to manage these. Most of these order desk now rely on synthetic order entry logic to manage this order flow.