NorthWest Biotherapeutics Inc (NWBO)

[exwannabe]

Most of the time, I've found that Fidelity actually fills most orders below my offering price, but only by tenths or hundredths of a cent.

Because often you are not seeing the real best ask. And if your bid is above that then by market rules it trades at the existing ask, visible or not. (technically it trades as a market buy up to the point of your bid). These "stupid" prices come from players who have the ability to use the 6 digits to get ahead of others.

If I want to trade w/o worrying about a fraction of a cent I will often put in a bid a bit over market.. It trades immediately at the best ask.

This works well for stocks with some volume, but for low volume stocks with large bid/ask spreads it can be expensive. In those you have to just sit a bit over the best bid and wait/hope to buy.