AMC Entertainment drama is exposing risks in $11 trillion world of indexing
Index funds are supposed to cut out the human-driven craziness that periodically infects markets, but the recent meme-stock fever proved the $11 trillion industry is far from immune.
The remarkable surge in shares of AMC Entertainment Holdings and a handful of other stocks is showing up in multiple exchange-traded funds, skewing portfolios, altering risk profiles and exerting outsized influence on prices.
Take the $68 billion iShares Russell 2000 ETF (ticker IWM). In the past week through Thursday,…