I'd question that. My wife is a former bond trader. At one point, the guys on her trading desk took her out to drinks, and one asked her, "So, are you still a virgin?" She was about 25 at the time.
Stereotypically, you have cash equities at one extreme and exotic derivatives at the other. Outside of banks, the culture at an HFT firm or quant hedge fund will be completely different from the culture on a "bro-y" bank desk.
Asking a woman who's 25 if she's still a virgin is a clearly loaded question - if she says yes then she's admitting to be inexperienced and should sleep with the the 'man' asking in order to learn the ways of the world, and if she says no then she's admitting that she's sexually active and therefore willing to sleep with a 'man' like the one asking the question.
Creepy assholes use this sort of tactic because they get off on making someone else feel bad. If you see it you really should call them out.