Zurich Insurance Group's shares declined after UBS downgraded the stock to "sell" from "neutral," citing concerns over valuation, debt leverage, and interest rate sensitivity. The downgrade highlights that shares are trading at a 30% premium to their five-year average P/E ratio, with limited room for appreciation. UBS also noted that Zurich's reliance on commercial lines, which make up 75% of its business, could hinder profitability as pricing lags inflation, while higher debt levels may restrict shareholder returns.