It may be close for the first year or so due to the signing bonus, but 3-4 years in if you're performing at the expected level at a trading firm you should be making double the 200-250k number, and I doubt the tech firms match that kind of compensation (at least for most people).

Another factor you may wanna consider is the opportunity cost -- how hard would it be for you to work at GOOG/FB if the trading firm job doesn't work out? And vice versa?