The Series 7 is for stockbrokers, and generally for those who work at brokerage firms such as Schwab, Fidelity, etc. It's a much broader exam and it will cost more to take it and to hold the license at a firm (I think FINRA charges around $500/year). The Series 57 is solely for deposit "prop shops" that take capital contributions in exchange for providing you with firm capital (usually at 20 times your equity). It's for day traders who want greater leverage than retail, and won't be helpful outside of the prop world.