Alphabet’s $500 Billion Sell-Off Signals Investor Backlash Against Run-Away AI Capex

History rhymes: the shock mirrors 22 Sept 2000 when Cisco plunged 16% after revealing ballooning inventory, marking the moment dot-com exuberance met balance-sheet reality. Big-tech dominance since 2010 rested on asset-light, ad-driven cash gushers, but the AI race has abruptly made them resemble the capital-hungry railroads of the 1870s or AT&T’s 1968 microwave build-out—huge upfront costs, uncertain payback, and highly sensitive to interest-rate cycles. Alphabet’s wipe-out highlights a structural shift: investors are no longer rewarding raw AI spend but demanding demonstrable returns, especially as policy rates hover near 4% and real yields stay positive. Over a 100-year horizon this moment may mark the transition from speculative infrastructure sprint to a disciplined, utility-like AI rollout—much as the 1920s’ electrification frenzy eventually birthed regulated power companies. Whether today’s giants adapt or cede ground will shape who captures the economic rents of ubiquitous machine intelligence in the decades ahead.