1.Stocks Added to S&P 500 Index Underperform Those Kicked Out by an Average of 23 Percentage Points Over 12 Months.
Barrons-Rob Arnott
Studying S&P 500 index data from 1989 to 2017, Arnott found that the stocks added to the index underperformed those that were kicked out by an average of 23 percentage points over the next 12 months Stocks added are almost always trading at high multiples. Discretionary deletions, when companies are removed for not meeting criteria, are almost always trading at bargain-bin prices. It occurred to me that no one had taken a close look at the “buy high, sell low” nature of indexes, exploring that as trading cost.
https://www.barrons.com/articles/rob-arnott-on-beating-stock-indexes-1527897602