Nothing change, everyone will continue their activity.
I am afraid that the BTC will then go towards 3k or even less. The altcoins will hit it even harder.
I dont know what i should do today, sell all my altcoins?
If you feel don't really comfortable holding altcoin, then decide by your self will you keep holding / selling your altcoin.
Try to make your own decision, following other people's advice just makes you confused. That's it's your asset, you should know the reason why buying/selling that altcoin but just don't regret went you make a wrong decision.