When you think of growing bitcoin safely, you get very few possibilities. Also it needs long time to grow compared to the methods which involves high risk factors. Upon ones need can decide which method to be chosen for growing hard earned bitcoin.
Best way to grow your coins is just keep on earning from signature campaigns only and just keep on collecting it, and one day when you will have enough coins u will yourself know where to invest and how to start your own business with it...
yes. the only safe way to grow bitcoins is do things/work and get paid in bitcoins. like signature campaign. social marketing. link sharing. designing, writing. posting etc.
all of investments which require you to deposit or pay first to earn money are obvious ponzi scammers.
Yes if you want a safe way to grow bitcoin then the bitcoin should always be inflow in your wallet even if for just a small amount because as time pass by it will be accumulated. Doing some work for bitcoin and signature campaign are two of the safe ways.Having an outflow like investing is risky because you'll never know if you can get back that amount again. Lucky for you if you profit from "investing" in those sites and have your ROI plus profit because others are not so lucky losing the bitcoin they invest.