So, this has been rounding my mind for since i started to believe in crypto.

I there exists plenty of wallets and various types, but this is a questions focus on trading wallets, and dealing with exchanges.
What happen when you are not using a wallet provided by the exchange (eg. Bittrex), but then you want to sell a coin the coin ASAP so you dont miss the peak.

HELP!

En méxico se acostumbra mucho comer quesadillas o cenar cereal XD

100% Yes 

Always check 4chan biz for new, but not advise 

I have a newbie question: If it is not recommended to store your coins on any Exchange sites, but on a Hardware or Cold Storage, then how are you supposed to exchange a coin before it dumps in matter of minutes?

thx