Originally Posted by twaddle
That's sort of my guess, too. But I don't think they do it for efficiency. I think they do it because they're hoping to get away with the lower bid as long as they can. Once a higher bid comes in that is within their spread threshold, then they reset.
Bottom-line: I want to be a market maker. Where do I sign up?
Googling a bit I see you can get a seat on the Chicago Board of Trade for a bit over $3 million, and CBOT website says you need to pass a few tests.
IIRC, the CBOT is one of the few remaining hold outs of the open auction system, which means you'd have a good excuse to dress up in bright guady cloths wear weird hats and such.
I think it would fun but I hear others a say it is a lot of w*rk