[Sebb767]

Yes, absolutely. I mean, if you put in years of preparation and are an active trader with a big portfolio, 500k$ is probably getting through the net. But if you're a newer trader, not much invested or not many positions? You're sure as hell getting some questions.

I mean, yeah, there might be a ten or hundred people who match this criteria, but market manipulation is a very serious crime and when people lost many millions, the SEC is going to pour a lot of resources into checking everyone.

EDIT: This is also assuming the hacker is American. I bet you a lot that this matches very few people in, for example, India.

[SilasX]

I don't think it's a stretch to assume this hacker group has some member with an active account, or to charitably take "you" to mean someone with (at least) a sporadic day trading history.