Here's the quote in context: "Among the stocks that just squeaked above the Russell 2000 threshold, a disproportionate share of the gains for May occurred on that measurement date -- in- deed, in the last minutes of that day." Here's another quote from the article: "If mischief takes place at the bottom of the Russell 2000, says Richards, the problem is small. Last year's additions to the indexes amounted to just 0.47% of the total weight." Maybe 0.47% of the very smallest and illiquid companies at the bottom of the RUT moved the NDX, SPX and DJI in the final minutes of trading on Friday, I don't know. It's just not a very compelling argument to me at the moment, especially without minute charts dating back to 1984 showing a strong correlation between the indexes and these small, relatively easily manipulated stocks.