Indexology®: Concentration Consternation | ETF Trends

“There are 3 kinds of lies: lies, damned lies, and statistics.”- Mark Twain

Earlier this week, The Wall Street Journal pointed out that a mere six stocks (Amazon, Google, Apple, Facebook, Gilead, and Disney) had accounted for more than 100% of the S&P 500’s year-to-date gains.  This degree of concentration (reminding some of the peak of the 1990s’ technology bubble) is said to raise “concerns about the health of the market’s advance.”  While the article’s arithmetic was correct, its concerns may be misplaced.

We don’t have to look back to the tech bubble to see a similar concentration of index returns: During 2011, 4 stocks (Exxon, Apple, IBM, and Pfizer) accounted for more than 100% of the total return of the S&P 500. This did not “presage a pullback,” however, as the S&P 500 followed with 3 straight years of double-digit gains.  What was similar about 2011 and 2015 through July 27 (the date of the Journal’s analysis)?  Aggregate returns were de minimis.  In 2011, the S&P 500 gained 2% on a total return basis (and was flat on a price return basis). The total return of the S&P 500 in 2015 was less than 2% through July 27.  In both periods, the return of the index was relatively low, making it easy for a small group of strong stocks to account for more than 100% of total performance.

Following a few positive trading days, incidentally, “The Only Six Stocks That Matter” now account for only half of the S&P 500’s year to date total return.  As of July 29, it would take 22 stocks to account for 100% of the market’s return.