There is also other means to invest Bitcoin, like investing in Bankroll, or investing in legit investment company that can give you 5%-20% profit annually, but I would suggest that you hold Bitcoin because it is more profitable holding bitcoin in the long term.
Legit businesses allowing you to invest won't offer you annual percentages of 20%, where even 10% is quite on the higher side. Just out of curiosity, name up a few legit businesses where you could earn more than 10% annually. In recent times I haven't even see any business offer you 5%. And those that do offer higher annual returns are mostly obvious scams, or likely to turn into a scam. It's not that easy as you seem to think.