Additional meaning of S&P:
Standard & Poor's publishes a large number of stock market indices, covering every region of the world, market capitalization level, and type of investment (e.g. indices for REITs and preferred stocks)
These indices include:
- S&P 500 -- value weighted index of the prices of 500 large-cap common stocks actively traded in the United States.
- S&P 400 MidCap Index
- S&P 600 SmallCap Index