After list in market, Many investor take a profit with sell their token. Thats why the price is down, because many people join ico to get fast profit. So when it listing they sell it. About recovery, serious dev will recovery their coin by buy it again and recovery price. But many dev just want to take profit from ico and dont recovery their coin.
It's true, investor who invest on presale/private sale that got a big bonus will sell some of their tokens to get a quick profit but remember bounty hunters also one of the reason why the price is fall after listed on exchange. No one can't control them though.
That's the investor techniques now, buy at presale and bonuses then sell when listed. But it is still risky to them in a way that they will need to research and get updates to know the project will succeed. Some cause of selling of Bounty hunters too.