I tried Currency trading on the Delta index simulator.
In the first wee I was up 50% and was sure I was onot an easy thing.
Then 1 day I didn't get back into the simulator after I finished work at 5 to stop trading for the night when I couldn't change it.
The next morning when I logged in I was nearly cleaned out!!
So basically, USD-YEN had been going 1 way for the daytime here, but after 5, it took a massive swing the other way.
Part-time Currency trading could probably work, but you will have to make sure you can get in to change your investments when you need to.