VeriSign shares fell on Tuesday after Warren Buffett's Berkshire Hathaway sold nearly one-third of its stake in the internet infrastructure and domain name registry company for $1.23 billion.

Here are some of the stories Wall Street is watching on Tuesday, July 29. Warren Buffett's Berkshire Hathaway (BRK-B, BRK-A) is trimming more of its stake in VeriSign (VRSN). Shares of Novo Nordisk (NVO) are being pummeled after warning of a slowdown in sales of its weight-loss drug in the US.

Famed investor Warren Buffett is booking profits and selling down his stake in internet domain registry Verisign (VRSN). Through his holding company Berkshire Hathaway (BRK.A / BRK.B), Buffett is selling 4.