Alphabet (GOOGL) shares jumped about 5% in premarket trading after Warren Buffett’s Berkshire Hathaway revealed a new stake in the tech giant during the most recent quarter.

Key Highlights

• Berkshire purchased 17.8 million Class-A shares of Alphabet, valued at around $5.2 billion.
• Class-A shares traded above $290 premarket, positioning the stock to challenge its all-time high of $291.31, set last Tuesday.
• If the gains continue throughout the day, Alphabet could log its biggest single-day increase since Sept. 3, when the stock surged 9% after a positive antitrust ruling.

Berkshire Hathaway’s Portfolio Changes

According to the latest SEC filing released Friday, Berkshire made several notable adjustments:

Reduced Stakes

• Apple
• Bank of America

Exited Completely

• D.R. Horton (homebuilder)

New/Add-on Investments

• Increased holdings in:
  • Chubb (insurance)
  • Domino’s Pizza
  • Sirius XM (satellite radio & audio streaming)
  • Lennar (homebuilder)