UBS Chief Executive Sergio Ermotti has bought 1 million shares in the Swiss bank worth 13.1 million Swiss francs ($13.07 million).
The bank confirmed that Ermotti was the buyer after the SIX Swiss Exchange posted on its website that a senior UBS executive had purchased the registered shares on Oct. 26, a day after its investor day. The stock has fallen by around a quarter this year.
"Our general policy is not to comment, but on an exceptional basis we confirm that it was our CEO," a spokesman said.
The news comes after Switzerland's biggest bank and the world's largest wealth manager last week reported a surprise 32 percent rise in third-quarter net profit thanks to a strong showing at its investment bank.