When I already have bitcoin, the first I will learn is trading. Although trading has risks like investing, but I think it's an alternative to increasing my bitcoin amount.
Yes, trading is a good investing to increasing our bitcoins if we can get constant profit from trading, especially trading altcoins because we can use small amount of capital and big amount of capital, so although we don't have much money in altcoins we still can do trading, there are chance to getting good profit and the other investment except trading is invest on the ICOs projects, that is good instrument of investment too.