i don't think to invest my bitcoin at other place especially at hyip or ponzi games
in my opinion i will invest my bitcoin at my wallet only till bitcoin price high enough for me
that is most safe way to invest my bitcoin

That's the right thing to do saving them for the future is the best investment to make as prices is tempted to go higher in future so if we manage to save enough amount of bitcoins then we can make good profits in future by selling them when price goes higher.
What you guys are are saying cannot be considered as Bitcoin investment, it is all fiat investment. As far as Bitcoin investment is concerned, there is hardly any possible legit opportunity on the Internet. Best ways I can suggest is to invest Bitcoins in altcoins and expect for positive returns