The Story of CAPM: The Risky Bet and the Rational Investor
A Meeting at Financia’s Stock Exchange Tower In the heart of Financia , where skyscrapers hummed with financial data, two friends— Ryan the Risk-Taker and Eli the Evaluator —stood at the entrance of the grand Stock Exchange Tower . Ryan, always drawn to excitement, pointed at the stock ticker flashing on a giant screen. "Look at SkyHigh Corp ! It jumped **12% today! I’m going all in!" Eli, the more cautious and analytical of the two, adjusted his glasses. "Wait, Ryan. Have you assessed the risk before chasing the return?" Ryan smirked. "Who cares? More risk means more return, right?" Eli sighed and pulled out a napkin. "Not quite. Ever heard of CAPM—the Capital Asset Pricing Model ? It’s what rational investors use to decide whether they’re being compensated fairly for risk ." The CAPM Formula: Understanding Fair Compensation for Risk Eli quickly scribbled on the napkin: E ( R i ) = R f + β ( E ( R m ) − R f ) E(R_i) = R_f + \beta (E(R_m) - ...