- trading to fiat/altcoins
- gambling
- investments
- lending
- hold
there is a risk on all those ways so I dont think there is no safe ways to grow your bitcoin.
I like only two ways of them. these are trading. and holding. investment also could be right somehow if you get a good and legit source of investment.
but gambling and lending are don't even part of earning money. if you lend some money from someone you have to pay him back one day. so this is not a way to grow bitcoin.
and gambling is the second name for loose for me. maybe some people earned lots of money with gambling. but even more peoples have lost also.
trading of altcoin is best way of growing bitcoin so far.