KBW said Berkshire's shares look "vulnerable" after the post-earnings rally, citing rich valuation and leadership uncertainty as Buffett prepares to step down.

Two months from now Warren Buffett will no longer be Berkshire's CEO and investors appear to be getting increasingly nervous about the year-end transition.

Berkshire's shares continue to trade in line with their intrinsic value, leaving little incentive for stock repurchases.

KBW said Berkshire's shares look "vulnerable" after the post-earnings rally, citing rich valuation and leadership uncertainty as Buffett prepares to step down.