Quote from gmst:
Hello Picaso, basic question. I see ask size is almost 1.8x of bid size. Doesn't it mean that there are many more limit sell orders in the queue compared to limit buy orders in the queue. Doesn't it mean that price will go down ??
Thanks for explaining.
First of all, cashcarewins has a point and DOM skew is the last (and optional) piece in the way I see the market puzzle.
Small differences in the bid and ask size are, in my view, meaningless (as with, for instance, small differences in up and down volume, or +/- 400 TICK readings). However, huge differences rock the boat.
What you say makes perfect sense - I thought the same at the beginning, but what happens is that size attracts price. So when you have a huge difference, you will see that in the ultra-short term price moves that way more often than not. That does not mean that the market will keep moving in that direction, though, since those movements tend to be algo-driven. You may also notice that you have higher volume at typically the same places as where stops tend to congregate, which also attracts stop-hunters.
One caveat: you normally will see these imbalances at suboptimal entry points, so I think it's better to use the skew to either add to a position or give your stop some room (or to wait a bit for the DOM to become balanced if you're looking to short/trade in the opposite direction), or to enter with an ultra-tight stop, rather than to enter new positions.
Edit: another caveat, this is the reason why the newbie move of placing a stop behind a large order or cluster of orders (for "protection") is not such a great idea and it usually results into being stopped to the tick.
When you see that skew, think like a bot.