Hi,
With SOPs aimed at advanced Finance degree programs, its wise to include "What" you intend to use the degree for and "Why" (i.e future goals job-wise).
Admissions Committees figure that most often the answer to the "What" = a job, and the "Why" = $$$ and lots of it $$$.
As a guide:
Its best to supplement them with technical detail on job prospects and to go into specifics with job duties(e.g licenses required, board exams - SOA, CFA etc).
For example: Potential Traders may discuss professional organizations to join and Depts which you'd like Trading for (equities/ fixed income/ gov. securities/mortgages etc).
Discuss what excites you about the traditional career progression path and what it ultimately ought to lead to (i.e long term goal - appointment to a goverment position etc.).
Show 'em that you're in it for more than just the $$$ !!
B-schools are looking to educate tomorrows corporate/gov leaders - signal the desire and ability to be one through your SOP.
My 2 Cents,
- j-z