Do some research. Listen to the solid points that have been raised here. Think. We all lost a ton of money today, but if you truly have NO clue why then you probably shouldn't be investing in any kind of stock, much less a venture stock.
In answer to your repetitive question:
People are selling because of what they see an untenable delay in the POET technology's progress. Lots of good stuff re the rest of the company's operations was brought up in the AGM, but for whatever reason, it's likely that some of those who were waiting for the POET "jackpot" got tired. Add the herd effect and stop losses and the price drops.