
Analysis
Is Index Concentration a Bigger Risk Than the Consensus Admits?
Ten companies now carry roughly two-fifths of the S&P 500, and the mechanics of passive investing transmit that weight directly into millions of portfolios.
Analysis takes a single development and follows it through the production chain to whoever absorbs the cost. Tariffs, shortages, rate changes and regulatory shifts are traced from origin to margin to shelf price. Written for readers wanting the causal path documented rather than a conclusion simply asserted.
Extended pieces following one change, a tariff or a shortage or a rate move, from origin to the company margin and consumer price it reaches.

Ten companies now carry roughly two-fifths of the S&P 500, and the mechanics of passive investing transmit that weight directly into millions of portfolios.