The Largest Energy Companies by Market Cap in September 2026

Saudi Aramco, ExxonMobil, and Chevron are the biggest companies by market cap in the energy sector

By Lyle DalyUpdated Sep 8, 2026 at 3:34 PM EST | Fact-checked by Frank Bass

Key Points

  • Saudi Aramco leads as the largest energy firm with a $1.68 trillion market cap in 2026.
  • ExxonMobil gained a 23.79% five-year return, heading U.S. oil giants.
  • Chevron employs AI tools to enhance operations in oil production.

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