Just go and learn crypto trading and trade it. Although it’s the market it can go the other way but it’s one of the fastest way to get more bitcoin. That’s also my strategy.
Yup! This is the best and I think the most popular way of growing your portfolio. But if you like easier way of earning then you should prepare for a greater risk of course. Try crypto gambling if you are brave enough 
. But I warn you, this is not for the weak hearted because the money moves faster here. Your money can double or can go to zero in an instant. But don't worry because you can avoid catastrophic loses as long as you are disciplined in money management.