[torero]

only a very small minority, usually market makers and specialists and floor traders. So very very small minority.

The best way I know is wait for the news to come out, then let the volume settle down a bit, then watch for higher high and higher low (to go long) or lower high and lower low (going short) from there on. You pretty much have an idea where it'll go next. Of course you have to keep support and resistance in mind. Fed news is one example I trade it. I trade emini Russell so not talking about stocks here. Stocks might require a different style.