Interesting what just happened with my buy order. I placed it for 100k at the ask of .0066 (AON) and it sat for about 20 minutes. Then I added .0001 to the ask of .0066 (so had it at .0067) and it almost immediately went through at TDAmeritrade at .0066:
Filled Buy 100000 UNVC Limit 0.0066 -- -- 14:35:05 03/25/20
https://ih.advfn.com/stock-market/USOTC/unive...NVC/trades