its never a good idea to put all eggs in one basket.
You should consider investing in many different coins, diversification is almost always a good thing.
fyi, BTC is the OG and a very reliable coin, it maybe fluctuating at times but will surely bounce back and stable itself.
the point is do not invest in one coin only, because this is the riskiest investments strategy
but try to invest in few coins,, better less than 10, so you can easily control it