Human traders still exist in the Chicago Mercantile Exchange/Chicago Board of Trade pits – even if trades from pits account for less than 2-3% fo the total volume.
Here are two videos from MrTopStep, a “Future and Options Educationnal Site” run by pit trader Danny Riley. This guy is pretty intense. The first video is about the Nasdaq outage :
The second video is untitled “Algos and Programs ran amuck!”: