Valuation metrics consistently suggest the S&P 500 stock price index is extremely highly-priced. How far can the stock market run when it’s already at record high levels? Although its valuation relative to its trailing 12-month earnings per share (EPS) is equally excessive, the S&P 500 was similarly priced at the start of each of the last three bull markets. It is worth considering how those past bull markets prospered in the face of equally lofty valuations—do their examples provide a pathway for the contemporary bull market?