I have placed orders to buy that were broken up for some reason by my broker. On Wednesday I placed an order for 60,650 shares. Instead of one trade the order was executed in three trades. One for 12466, one for 47534 and the last for 650. A few weeks ago I placed a another buy order which was broken up with one trade to complete the order was 50 shares.
I just asked my broker why trades were broken up and he said that some brokerage houses will do that on large orders on penny stocks to help avoid market manipulations.
I just switched to Charles Schwab a few months ago and had the same issue when I transfered my account from another brokerage firm to Schwab so I dont know if it is just Schwab that does that or others do also.
That could explain the small order trades.