Financial pros have long urged investors to hold diversified portfolios—and the risk posed by stock indexes’ persistently heavy tech stock concentration has amplified those calls. Over that period, investors diversified into bond and international stock exchange-traded funds amid an uptick in inflation expectations, skepticism over companies’ spending on artificial-intelligence buildouts, and heightened geopolitical concerns. One ETF hoovering assets suggests that some investors are also diversifying by flirting with non-capitalization-weighting strategies.