There could be many reasons why individuals sell. Some might...

There could be many reasons why individuals sell. Some might want to put the funds elsewhere for a higher short term profit... they might need the funds to cover other losses... they might simply be scared of what's going on in the markets atm and want to salvage what they can... or the company simply may no longer meet their investment/trading criteria (stop losses, etc.)

It's up to each individual to make what they will of the situation and make their own decision on what to do. Perhaps talking to a licensed advisor may be appropriate if you're not sure of what to do with your position.