Five line charts compare cumulative U.S. stock market returns over historic eight‑year investment cycles for major innovations, including AI currently, telecommunications starting in the 1990s, oil and gas starting in the 1980s, post-World War II auto manufacturing, and railroads starting in the 1850s. Each line shows considerable volatility. Some cycles rise near or above 100% before declining. Some eventually fall below a dashed trend line representing long‑term average excess returns since 1926. The AI cycle, shown only through approximately its first three years, currently tracks above the long‑term trend.