Why does SEBI investigate only Crashes

I never really understood why SEBI investigates only crashes. If there is a flash crash it investigates, if some script crashes 10% it investigates.

Does it sleep when the same script has gone 100% up? Why are we so biased for crashes? Isn't it the way to remove the excesses in the market ? Shouldnt we be more careful when excesses happen? It is so funny when people give 101 theories why a stock should be up and hardly find one theory why a stock should be down.

On the same note, I should narrate this experience. I have bought CINEMAX when it was in around 40. It came down to 25 and then went for demerger and didnt trade for a month or two. And then it split into 2 companies.

It have me 100 shares of some cinemax properties and 100 shares of cinemax movie I guess.

Do you know where it opened. It opened at 120 and moved into 200 before PVR bought it.

And Cinemax properties in high 10s.

Now, someone please tell me this is not manipulation and SEBI doesnt need to investigate.