I'm trying to keep track of the source of the their fortunes. Heroes only, not villains for this thread. Feel free to add others. There are a lot of rich comic book characters, and I know I've missed some.
- Bruce Wayne always inherited his wealth from his father, though that wealth has grown a lot
- Oliver Queen - I know once the business existed it was inherited (and lost), but really don't know about golden age or even the silver prior the changeup (which I consider to be bronze)
- Ted Kord - per the 1986 series, he took a "hole in the wall" company and made second to only STAR labs and earned the vast bulk of his money by being a brilliant scientist and businessman. That business acumen (and money) didn't seem to stick though JLI and beyond, from what I know. Not really sure what later status quo was.
- Mari McCabe - as far as I know, she made her own fortune, but I haven't read much of her
- Steve Dayton - he was extremely rich in the 60s-80s (5th or 6th richest man in the world and much richer than Bruce), and I know he earned a lot, but I don't know if he started off rich, less rich, or not rich
- Kon-El was temporarily rich (though I expect to a much lesser degree), and earned that money via capitalizing on his fame
- Booster Gold was also at times rich. Earned via endorsements and did some stock market investing (with future knowledge)
- Kathy Kane (silver age) - I have to admit, I'm not sure where her money came from
- Victor Stone (Before new 52) inherited from his father
- Garfield Logan - at one point he was to have inherited a million dollars, but don't know if that ever came to fruition (don't know if he ever made it to 18 to have control over it, given DC's refusal to let him grow up).