Could be a few reasons. If I wanted to sell 100,000 shares for...

Could be a few reasons. If I wanted to sell 100,000 shares for 2.1 cents and there were only two people looking to buy shares at that price, the first guy in the queue has an order for 99,999 shares and the 2nd guy 50,000.

You would see one sale 99,999 and another sale of 1 share. So the 2nd guy only had a fraction of his order bought until someone else wants to sell at that price and then his order would be first to be executed.

The 2nd reason could be a broker wishes to sell a tiny parcel to manipulate the SP. 1 share has the potential of putting it in the red. This may force more people to sell out of fear in which the broker has buy orders in for the lower price.

There are more reasons but most of it will be guess work. Good looking out though.