Apple Inc.'s stock rose nearly 6 percent to $445.29 in midday trading Wednesday, bringing the iPhone and iPad maker's market capitalization to $415 billion.
Meanwhile, Exxon Mobil Corp. shares are down 1 percent at $86.52. That gives it a market cap of $414 billion.
Apple said Tuesday that net income in its latest quarter more than doubled, while revenue grew 73 percent.
Cupertino, Calif.-based Apple first topped Exxon as the most valuable company in August, then fell back to second place. The Irving, Texas-based oil and gas giant had held the top spot since 2005.
Apple overtook Microsoft Corp., now in the No. 3 slot with a market cap of $247 billion, in 2010.