I work for a brokerage firm as a Supervisor. I am on salary and am required to work overtime. Just this week about 8 hours of overtime worked. I was informed Friday at 9 that I had to work all weekend. So i am looking at a min of 24 hours of overtime this week. I supervise 4 people. Is my company required to compensate me for this overtime?

There are a number of possible exceptions to the overtime rules, but since you supervise, the most obvious exceptions is the Executive classification. I have included a webpointer to the factsheet. If you qualify as Exempt under this exception, then you are never entitled to paid overtime.

http://www.dol.gov/esa/whd/regs/compliance/fairpay/fs17b_executive.pdf