does this happens?

I have been wondering about something lately. Can one manupulate market like this?

A fund manager is managing say $10M portfolio. He has got access to half a dozen trading accounts. He spots good fundamental and early in bullish trend stock (e.g AYN last month). He starts to buy large volume consistently.

This will make the market very bullish and retail investors jump in and buy stocks (e.g: AYN till yesterday). Now fund manager starts to sell his shares from one trading account to another in persistant large volume. Novice investor panics and starts to sell. Stop loss trigger goes on. At the mean time fund manager takes benefit of it collects them on the way down and cycle continues.

What do you think? This happens? and if it does, is it legal?