Ha! 1000 seems to do the trick, but any size 100 and up will move the price. Last 7 seconds, and hit the Ask. Glad someone is taking over because I'm not supposed to buy in the last 10 seconds now.

I waited until 5 seconds left today and they filled my 1000 at 4:00:00 pm (you can see it on today's tape), so it didn't count. Gotta be in by 3:59:59 to get the last print.