Oh, "they" can do whatever they want. But a lot of the increase in program trading is better and faster data feeds, more bandwidth and increased computing power. Instead of having button pushers, they now are just turning the computers lose. And unless you can see the whole trade, the individual parts may not make any sense. They buy this, sell that, and hedge over there and that is one "trade". The computers are continually scanning all stocks, futures, options, everything, looking for profitable trades. One could look at it as legal "stealing" made easy. Da boyz have found a way to skim off top and they don't even have to push any buttons. Just turn the computers on and walk away. Come back at the end of the day to see how much they've made.
You should hire the programer looking for a job at your store to program you a trading computer. Tell him he gets half of everything he makes you. <g>
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