I've spent the last five years trying to forget everything I know about technical analysis
...which is a lot.
I'm not talking about fundamental trading. Although, if you're a position trader, you should probably have a very good feel for the fundamentals. I'm talking about the importance of being able to read the price action when day trading.
A person can look at a chart for about 1 minute and make a note of major levels. Knowing where the numbers are is not the problem. Not knowing how to read the order book is the problem. Making an entry or exit decision
just because the price is a level on a chart is the problem. A scalper knows where the number is but he also has a really good feel for whether the level will hold or not because he knows how to read the volume. There are plenty of times when it's pretty obvious which way the market is going. You certainly can't know if it's going to go another 20 ticks but you can see that's it probably going to move another 3 or 4 ticks, at minimum, and there's no reason to buy at 20 if you're pretty sure you can get 16s.
If a big day trader is long 500 contracts and the market is 4 ticks against him, he is dying. His stomach is churning. He doesn't care what the charts or indicators say at that point. He's down 4 ticks and he's not losing 8. If the market continues to break, he is going to dump his position. When he dumps, he has an impact on the market. Will his selling move the market down a lot? Don't know. Depends on whether or not anyone wants to buy 500 here. If they don't, he moves the market. When he moves the market, you want to be on the right side of that move or at the very least, you want to stand aside and not be going against it. Knowing where major levels are is fine but understanding what's actually happening in terms of how many contracts are being traded at what price is much more important. Understanding the mindset of huge scalpers is more important.
Plus, while a technical trader is sitting around waiting for a certain price to get hit, scalpers might see three different good opportunities to make money just by reading the order flow.