The core claim—chip stocks' S&P 500 weight hitting a record 19.7%, nearly four times its 2020 share, amid the AI boom—is corroborated by multiple independent outlets. Investing.com and Yahoo Finance both report the exact 19.7% figure, attribute the data to Citadel Securities' Scott Rubner, and confirm it is nearly four times the ~5% weight from June 2020. The Odaily newsflash that served as the source lead aligns with these. The concentration and valuation concerns mentioned in the claim are also reflected across sources.