While I agree with the posters above, I think we may have conflated volatility and what the OP actually wants (which I wouldn't knock you for as what the OP asks for is indeed poorly defined). If the OP is literally concerned with what he said in his first post (the speed of bid ask changes), then all of these markets are gonna be too fast for a human being to analyze meaningfully a lot of the time. Your brain plays tricks on you. You can't see every change in bid ask size, they're too fast and too frequent, your DOM probably already is smoothing them out to some extent. You'll discount the size changes that happen too quickly because they either were around too short of a period of time for you to contextual them or they just won't even be displayed. Your brain will focus on the size changes that are freshest and you'll continuously trick yourself into thinking you understand an extremely complex and fast evolving system. I don't recommend it. You need computers to really do any meaningful analysis of frequency and magnitude of size changes. Gotta play to your strengths, and they aren't digesting hundreds of updates to a number per second as a click trader. Maybe "fast in terms of bid ask" has nothing to do with the quantities quoted and I'm just reading his request incorrectly. If "fast" is indeed just volatility, this isn't even a worthwhile question for me to type all this for. It's also possible he could define fast as just absolute count of bid ask price changes. For example, ES is much less volatile than CL, but it puts in an awful lot of ticks up and down just gapping and filling without much real actual volatility all day. That could be construed as "fast" too I suppose.