I believe you're referring to altcoins investment and not Bitcoin because Bitcoin can't fail or be unsellable, if Bitcoin does fail then we won't have a market anymore. Altcoins are very risky investment, for your example use investing in Bitcoin and holding and then trading of Bitcoin. Holding has been more profiting than trading and those who held their Bitcoin instead of trading at are the most successful.
Trading can be profitable but you have to go through risk daily and some days mightn't be profiting and then if you don't have the emotional strength to put those losses behind you, it'll affect your other trades. There's nothing bad with day trading and it isn't a jobless work but not just worth it, just buy and hold.