When the market has a bad down day people who have stocks on margin have to liquidate holdings (often their "winners") to avoid margin calls.

So, assuming POET is a winner for most (I know it still is for me), if I had a margin call I would be selling some to cover the shortfall.

POET is reacting exactly the way I would expect given the market conditions.

Just wait until the market really collapses and see what happens.