What do you think will happen tomorrow with the BTC (up or down?) if the stock markets worldwide crash again?
I dont know what i should do today, sell all my altcoins?
All financial instrument are connected, the effect like domino, one down another will also falls. That is general prediction could happen but don't panic, you only need to see your stop loss or cut loss, hold is not an option. If far away from stop loss just wait but if reach it never wait to cut loss, that's is your safety and right thing to do. Want more safe just sell all coin you have switch into currency and wait until halving, your choice.