Tue, 02/21/2017 - 19:12
#1
someone gave you a deal
It is possible to post an offer to sell, for a lower price than the lowest current offer to buy. It doesn't happen often, because it doesn't serve rational self-interest, but sometimes people do it in an attempt to lower energy prices, or as a joke.
So if you have the lowest offer to buy, and someone posts a lower offer to sell, then the transaction occurs, with the difference returned to the buyer? I haven't experienced this myself, but that's my guess. Cheers.