can i invest 10$ BTC ?

Few days ago I read a story of someone in reddit who has invested $100k in Bitcoin. This happened about a year or so ago when everyone was talking about cryptocurrency.
He left the money there untouched till noticed a year later that the value has dropped 10 times .
I cannot find the link to that story in reddit right now but he said that he's been f***ed up by doing this.

You can invest $10, no big deal