OTC is sketchy when it comes to fills.
I get instant fills on Nasdaq.
In FNMA however this is what I have observed:
In normal days, I can get filled at ask or bid (buy or sell, respectively)
When I played the first bounce (Wed correction), I put buy orders 10 and 20 cents above ask after spotting the bottom at 2.30. I got filled at an average of 2.39. I sold also early at 3.60 when everybody was still buying, coz when the selling starts, man, another pain getting filled.
My broker told me that the OTC takes orders and fills them in a random order. I have seen that from my experience. Sometimes U would put 2 orders and the better one may not get filled, weird.