It's not stupid at all, if you really need to cash it out then why would it be called stupidity?? Different People, Different Views on whether to sell bitcoin or not. if they feel that bitcoin will still fall down for the following days then its a wise decision to sell it out, after all no one could tell when will it rise up again.. on the other hand if one feels that keeping bitcoin woulld be more beneficial then its his or her call.. Its a big No No to call it stupidity..