According to @KobeissiLetter, Nvidia (NVDA) has averaged an 8% share of the S&P 500’s market cap in 2025, the highest percentage of any company in the index this year, source: @KobeissiLetter. According to @KobeissiLetter, NVDA has surpassed Apple (AAPL), which led the index by market weight for the previous six consecutive years, source: @KobeissiLetter. According to @KobeissiLetter, NVDA’s current market weight is the largest for any single company since 1974, source: @KobeissiLetter. According to @KobeissiLetter, historical leaders included IBM (IBM) dominating for 15 years in the 1970s–1980s and General Motors (GM) leading for 18 years during the 1950s–1970s, source: @KobeissiLetter. In a free-float market-cap-weighted S&P 500, an 8% NVDA weight mechanically implies similar proportional exposure for index-tracking funds, concentrating performance attribution in NVDA for broad-market portfolios, source: S&P Dow Jones Indices.