I would say that it depends on the coin you're investing in. This year most altcoins hasn't been doing quite alright, but Bitcoin has been increasing in price alongside a few other top altcoins like Ethereum. So it all depends on the coin that you bought, you should check and see whether that coin has any potential to grow and if you feel like it doesn't, then you should sell it and invest that money in Bitcoin and that would be the best thing to do since you know that Bitcoin is already doing alright. Although I don't know when Bitcoin is going to drop. Everything here is all about risk, but one thing I like about Bitcoin is that no matter how long it takes, it will always go back up and you will recover.