My .0065 buy order finally executed 16 min before closing. You are right, there were multiple opportunities for my order to execute during the day. It's not the first time I have had my low bid execute just before closing. That's why I didn't panic and raise my bid, to .0066 or .0067. My feel is that the MM's are just cleaning up lose ends at the end of the day, ie, all the price bouncing just before closing.