Sorry... How about this... "Using time travel this way makes you a super villain, therefore I must stop your dastardly plot!"
Much better. Now we will have a time travel war. Me trying to do dastardly things, and you trying to stop me. If only you could find out when and where I am.
Didn't he travel to 2015? I'll be looking for flying skateboards and a Cubs World Series victory here soon.
The correct answer is immortality. You don't need stupid time travel gimmicks to get rich when your investing period is forever.
That is where the tech comes in. My friends at S.H.I.E.L.D. have been working on a wormhole generator.
Two things that I find to be cope outs... Time-travel and "absorbing other heroes powers". Both have to have some kind of limitations.
That didn't officially become a good answer until we got past the 12-21 Mayan Apocalypse. What good would immortality be if there were no one around to lord it over?
You need to be more specific. Like, I'll always be 25 years old or something. You could have hands and feet falling off when you're 246 years old.