Wall Street has been on one heck of a roller-coaster ride since this decade began. The revered Dow Jones Industrial Average (^DJI 0.11%), broad-based S&P 500 (^GSPC 0.38%), and growth-stock dominated Nasdaq Composite (^IXIC 0.54%) have endured two bear markets (in 2020 and 2022), as well as a period of investment euphoria (2021) that sent all the major indexes to new highs.
Through the first eight months of 2023, euphoria looks to be back on the map. The S&P 500 and Nasdaq Composite are higher by 15% and 31%, respectively, as of the closing bell on Aug. 28, and all three major indexes have reentered a bull market, based on at least one definition.
But before uncorking the champagne and welcoming back the exuberance than sent the Dow, S&P 500, and Nasdaq Composite to new highs just two years ago, investors need to face one very clear fact: Stocks are expensive. Historically…