This is what client-facing desks are seeing at various banks across Wall Street right now. One example below:
PLEASE DO NOT ENTER ANY MARKET ORDERS FOR TWTR UNTIL AFTER THE STOCK STARTS TRADING. THESE ORDERS ARE CAUSING A LARGE NUMBER OF REJECTS WHICH MAY DELAY ENTRY OF YOUR ORDER.
THANK YOU FOR YOUR CO-OPERATION
Translation: slow down damn it, there will be more than enough shares sold to satsify all demand. Why is there a scramble? Because of this: TRADING RANGE: TWTR (NYSE): 40.0000-44.0000