The S&P 500 is down 24.5% so far this decade on a price basis, which is much worse than the Dow's decline of less than 10%.  But only three of the ten S&P 500 sectors have underperformed the index as a whole in the 2000s -- Telecom, Technology, and Financials.  Telecom and Technology led the way down during the tech bust in the early part of the decade, while Financials led the way down during the credit crisis of 2008 and early 2009.  The Consumer Discretionary and Industrial sectors are both down this decade, but they have outperformed the S&P 500.  Five sectors in the S&P 500 are up this decade, with Energy leading the way gaining 107.36%.  The Consumer Staples sector is up the second most at 34.61%, followed by Materials (25.3%), Health Care (10.16%), and Utilities (7.07%).

The Financial and Technology sectors have the largest weightings in the S&P 500, and this was a big drag on performance for the index as a whole.  If the S&P 500's sector makeup were equalweighted (a 10% weighting for each sector), the index would have done much better this decade with a decline of just 1.02%.  Seems like a good ETF idea!