Turning today to week-over-week shares outstanding changes among the universe of ETFs covered at ETF Channel, the largest outflow was seen in the Financial Select Sector SPDR Fund (XLF), which shed 9,950,000 shares, or a 1.9% decrease week over week. And on a percentage change basis, the ETF with the largest outflow was the Proshares Ultra DJ-UBS Natural Gas (BOIL), which lost 300,000 of its shares, for a whopping 18.5% decline in outstanding shares.