Berkshire Stock Sees Weird Trading. The A Shares Pop While B Shares Dip.

Berkshire Hathaway’s A shares ended Wednesday roughly at parity to the B stock before moving to a 1.6% premium on Thursday’s close. (Photo by Jaap Arriens/NurPhoto via Getty Images)

There was some unusual trading Thursday in Berkshire Hathaway as the Class A shares spiked up 1% in the final minutes of the session while the Class B shares dipped.

The net result was that the Class A stock finished Thursday with a gain of 0.8% to $719,850, while the Class B shares were down 0.9% to $471.88. That gap is a rare as the two classes of stock normally move in lockstep with no more than a 0.1% to 0.2% daily difference in price change.

It is unclear what caused the late-day buying in the A shares, but it looks like it will reverse Friday. The A shares were down 1% to $713,000 in after-hours trading and the B shares up 0.4% to $473.83.

The A shares ended Wednesday roughly at parity to the B stock before moving to a 1.6% premium on Thursday’s close. The A shares have traded close to parity with the B stock for much of 2025. They can trade at a premium to the B, but not vice versa since each A share can each be converted to 1,500 B shares but not the other way around.

More than 60% of the shares outstanding are B shares and the B shares are more liquid, meaning that weird trading activity can happen more easily in the A shares. The B shares also are in the S&P 500 index while the A shares aren’t.

Write to Andrew Bary at andrew.bary@barrons.com