Here's a long overdue explanation. Long overdue, because every serious trader gets to a point where one monitor just isn't enough.
Traders use multiple monitors in different ways.
Some might put up several Level II screens at once in order to see all the bid and ask prices for each stock. Then they may place charts for those same stocks on still more monitors. And they might keep another monitor in reserve for chat and yet another for news. Still other traders find they need more monitors as their experience grows, says John Chittenden, CEO of TriKinetic Technologies. Chittenden's Austin, Texas-based firm designs and builds trading computers.