Benjamin Graham, the father of value investing, would have been 125 years old this week. The idea he fostered—buy cheap stocks and hold them for superior long-term returns—is looking geriatric, too.

Faster-growing, higher-priced stocks have outperformed by such huge margins recently that the long-run advantage of value stocks has withered away. Will that last? Probably not. Was Graham wrong? Almost certainly not. But value investors shouldn’t try to hide how dark the evidence looks—and they should ponder whether the world...