According to @KobeissiLetter, Nvidia (NVDA) now represents roughly 8% of the S&P 500, the largest single-stock weight since records began in 1981 (source: @KobeissiLetter, Aug 9, 2025). @KobeissiLetter reports that the only other company to exceed 7% was Apple in 2023, and even the 2000 Dot-Com Bubble did not see a single stock dominate to this extent (source: @KobeissiLetter, Aug 9, 2025). At an approximately 8% index weight, a 1% move in NVDA mechanically contributes about 0.08 percentage points to the S&P 500’s same-day return, increasing index sensitivity to NVDA-specific news and earnings for SPY and ES futures traders (source: @KobeissiLetter, Aug 9, 2025). For crypto traders, this concentration makes NVDA-driven S&P 500 swings a notable input on cross-asset risk dashboards, warranting monitoring of BTC and ETH during US hours when NVDA-related moves occur (source: @KobeissiLetter, Aug 9, 2025).