That salary is not for someone "right out of college" with a bachelor's degree, though.
The poster's son has a PhD in Physics - which is a math heavy major - not right out of college with a Bachelor's either.
He is probably doing financial modeling. Its a very lucrative field, but its something you need a graduate degree in a math heavy field to generally do.
I knew a guy who's fiancee was hired out of Stanford into Wall Street with a Masters at $300k with a similar background then years ago.