Looking today at week-over-week shares outstanding changes among the universe of ETFs covered at ETF Channel, one standout is the SPDR S&P 500 ETF Trust (Symbol: SPY) where we have detected an approximate $4.5 billion dollar outflow -- that's a 1.2% decrease week over week (from 918,330,000 to 906,980,000). Among the largest underlying components of SPY, in trading today Berkshire Hathaway Inc New (Symbol: BRK.B) is off about 0.3%, Alphabet Inc (Symbol: GOOG) is down about 0.2%, and Exxon Mobil Corp (Symbol ...