Saudis, ETFs could speed oil decline: Citigroup By: CNBC.com News April 13, 2015 at 15:11 PM EDT Citigroup says inflows into crude-linked ETFs have created "significant froth" and could exacerbate a downside correction in the second quarter. Read More >> Related Stocks: Citigroup PowerShares DB Agriculture Fund PowerShares DB Oil Fund US Heating Oil United States Oil Fund