S&P500 Buyers & Sellers March 16, 2020 9:08am by Barry Ritholtz Source:ETF Stream The (March 11) chart above shows three of the largest S&P500 index funds in the world from State Street, BlackRock, and Vanguard, Note these are the exact same index holdings, simply in different ETF wrappers: -The State Street Spyders (SPY) are the professionals’ choice. -Blackrock iShares (IVV) and Vanguards (VOO) are preferred by RIAs and individual investors. As the sell off progressed, what happened was fascinating: the Wall Street pros were net sellers and the Mom & Pop Main Street investors were net buyers. Some of this is attributed to different timelines between investors and traders, short term and long term. But I also suspect some of this is explained by psychology: Which S&P500 investors are less emotional and looking to take advantage of a price drop, and which ones are stressed, perhaps in a bit of a panic. It is an intriguing differential: I cannot recall ever seeing the exact same asset handled so differently at the same exact time depending upon the ETF issuer — but not the ETF. More on this later . . . (Update:Bloomberg column is posted) https://ritholtz.com/2020/03/buyers-sellers/
SPY is used by traders because that's where the volume is. IVV and VOO by investors because of lower expense ratio