UBS's head of U.S. equity derivatives strategy said she expects the S&P 500 to fall at least 10 per cent from its peak in a month. ‘I am tactically bearish on the next two months,’ Rebecca Cheong wrote in a report to clients on Tuesday. ‘The slightest disappointment in upcoming economic data could trigger a massive pullback.’ She advised investors to buy tail hedges on ETFs to protect against losses, citing the iShares AXA Russell 2000 ETF (IWM), the Financial Select Sector SPDR Fund (XLF US) and the iShares AXA iBoxx High Yield Corporate Bond ETF (HYG) as top picks.