> We have to remember that for every bitcoin sold (at any price), someone on the other side of the transaction is still buying those bitcoins

An alternate explanation is that supply is holding out, demand is spooked, and existing trading activity has little relation to supply and demand. Economic liquidity is not equal to book liquidity and trading volume isn't equal to the health of a market (especially when Bitcoin holders can generate fake volume at a very low cost). This is why buying assets headed south--called "catching a falling knife"--is a classic trap for amateur traders.

This is going to be especially true for Bitcoin because there's no viable way to short it that I know of--no way to depress trading demand unless you're unfortunate enough to own some already. There's nothing that can try to force Bitcoin to it's supply-demand equilibrium price, nothing except time.