For sure doing both makes no harm.

Trading means taking some risks, more you can earn but there is a chance of losing as well.

Bounty is minimum risk taking business but your success also depends on your skills and status.

 You can always improve yourself and do your best with campains. Important to sign for a good bounty not a scam one.

Then when you get your tokens comes a question to sell or hold. So bounty goes hand in hand with trading.