Level 2 is pretty useless now because of ECNs that allow you to hide your orders. Back in the old days (before 2003) if you had a large order and you put it up for sale for example, it would show on L2. That would allow daytraders to see that and basically infer that with such a large order for sale, the price most likely would go lower. That set up a scenario where daytraders/hedge funds could step in front of that and lower offers in front of that order.
That's basically the idea.
Now, if you have say, 500k of BRCM to sell, you place it with an ECN (electronic communication network) like the Island book or ARCAnet or the other big one I can't think of the name right now, your order is 'hidden' in that it will only show 100 shares at the current inside price. That means that it's nearly impossible now to determine much from the level 2 quotation system without really paying close attention to how the orders hitting via time and sales are affecting the current offer. So, if you see 1000 little 100 share blocks hitting the current inside bid which only shows 100 shares, but that MM at that price doesn't budge, you know something is up.
So, you're stuck with price charts.
