Bitcoin is probably ok but you should always be careful because it is definitely a risky investment.

I would because I can just as easily sell it back to fiat and vice versa.

Well if the price goes down some miners will just turn off their rigs and difficulty will go down instead so it doesn't really matter for mining as a whole. Of course the ones with the lowest profit margins will be hit when that happens though.

At the moment it seems to be mostly speculation and new countries pouring a lot of money all of a sudden into bitcoin. Historically these speculative cycles have been alive but the general trend of growth is linked to the increased usage bitcoin has been getting year after year to the point where the bitcoin network can't even handle all these transactions anymore.