What is the name/term for the function that allows you to graph the risk-return of a portfolio?

I believe it uses a security's Beta, along with other things, to pick out the best mix of various securities, in order to get the best reward to risk ratio. When graphed, it looks like a parabola (U) on its side, opened to the right (like a C). I simply forgot the name of the terms for it, including what the best stock pick area is called (just remeber it's some sort of fronteer).

What is the name/term for the function that allows you to graph the risk-return of a portfolio?
Sharpe ratio? Efficient frontier. See this link:
Reply:I believe you are thinking of the efficient frontier...taking that a step further, however, you actually make your decision along the SML. In order to calculate the risk of a stock , you would use the Capital Asset Pricing Model (CAPM) to determine where on the SML that stock lies (depending on the stock's correlation with the market returns; or its beta) Below is the equation:





Risk-Free Rate of Return + (Market Rate of Return - Risk-Free Rate of Return) x Beta of stock





I hope this helps