http://pages.stern.nyu.edu/~adamodar/New_Home_Page/datafile/histretSP.html

We can find there that the long-term (1928-2016) "arithmetic average" expected return for US S&P-500 stock market index (Rm) was xx.xx% per year, while the long-term (1928-2016) "arithmetic average" expected return for US risk-free 3-month T-bill (Rf) was x.xx% per year.

Also, via http://finance.yahoo.com, CAT's "Summary" or "Statistics", we can find CAT's systematic risk "Beta" value to be xxx.

Collect those above data quotes from web sources, then plug them into the CAPM formula E(Ri) = Rf + BETAi * [E(Rm) - Rf], and calculate "what is CAT's E(Ri)? In other words, when the US stock market reaches the equilibrium, what should be the long-term annual expected return to be fair for CAT stock?"

Risk Premium Stocks - T.Bills Geometric Average Stocks -T.Bonds 1928-2016 | 9.53% | 3.42% | 4.91% 1967-2016 2007-2016 10.09% 6.88% 4.83% 0.73% 656 % 4.58% 6.11% 5.26% 6.15% 4.62% 3.42% 2.30% ST: Short term (3-month Treasury bill) LT: Long t0-year Treasury bond) Last updated: January 5,2017