trading the best grow your bitcoin
but you must have skill trading, prefect skill, because without skill is nothing you can increase and grow your bitcoin
you can lost all your bitcoin is without skill
without skill in high risk high return you can try investment in cloud mining, but majority ponzy, so someday scam
Trading can give you good profit in short time but you need to have skills for that.You also need experience to be succeeded.With proper skills and experience you could be succeeded in trading easily.And always trade with that amount which you can afford to lose.
Also opening a lending service and fill the loan to trusted people is also a good way to increase bitcoin.But you need to be careful on that.