That depends on what one considers a real startup. I've been at three that referred to themselves as such (really four, but that one was already public when I joined).
Two tiny ones were disasters - pocket change when one IPOed and only a sense of relief escaping the other (like joining the Witness Protection Program), though some alumni went on to get rich on famous stuff. The largest was a great success, lucrative and a good education about the world - but there was a lot there before me.
