-Trading BTC USD and earning profit from it
-Exchanging crypto's and earning profit from it
-Lending (that is a bad method IMO)
First point: risky but if you are good on trading you will earn good money
Second point: speculate on some young or already consolidate altcoin is risky too....but if you jump on board on somne pumping it's possible to make a huge amount of money....just jump down before dumping
Third point: agree that is a bad method....i don't trust to give my money to others
Firstly, when it comes to price, risk is obviously involved...
Secondly, speculation is what we are based upon currently for the value of Bitcoins, and so does the same thing influences altcoin markets too... Go for least volume markets that are going to get delisted, many will get pumps for sure without any reasons...
Third, lending might be bad, but you have your own decisions and need luck too, but you can only lend very trustworthy persons...