I got the question "what is principal ?"
It means if I invest 1 btc in BTG, and i have the opportunity to sell at 30% profit, I will cash in 1 btc (and not 1.3 btc), and keep the 30% profits running with a sell order at my second target. So the investment becomes risk-free, even if btg "disapears". And if it does a huge pump, you are still ready with some stashes from a very low entry.