The best way to grow bitcoin, is to investing them in some secure company.or maybe you can landing them to anyone you trust, with property collateral, and returned more.There is another way, is to investing in some cloud mining sites, like genesis-mining.but you should not invest so much. because many of cloud mining sites are scams.so be careful for doing that.
YES, I agree if your bitcoin put in different secure investment, were accumulate of lots of interest so it will grow and another things is in trading company that trusted of many people, you can get more return so its grow again. Anyone needs money, so they can borrow in trusted company even they can pay big interest. so this is one way how to grow your bitcoin.