The Passive Tax: How SPGI and NDAQ Monetize Silicon Concentration

The headline equity benchmark is up 14% this year, yet beneath the surface, more than four in ten S&P 500 constituents are actively underwater. The broader U.S. economy is not necessarily booming; rather, the cap-weighted index is being heavily subsidized by a single supply chain. Extreme capitalization weighting in Silicon Valley technology leaders has transformed benchmark index mechanics into a self-reinforcing passive flow flywheel.