As a market capitalization weighted index, the S&P 500 (^GSPC) has undergone some noteworthy sector shifts over the years.

For example, financial services spent significant time as the S&P 500’s largest sector weight. Then financial crisis struck, punishing bank stocks and sending financials to a weight of less than 8.6% by the March 9, 2009 market bottom.  [Comparison of Major Sector ETFs]

These days, technology leads the way at 17.7 followed by financials at 16.3% as of Nov. 22. Only materials, utilities and telecom do not command double digit weights within the benchmark index.

S&P 500 Sector Weights

Chart Courtesy: State Street Global Advisors

Financials’ spot in second place makes some sense as the Financial Select Sector SPDR (NYSEArca: XLF) is the second-best performer among the nine sector SPDR ETFs since March 9, 2009. XLF has posted a gain of 271% through Nov. 22, well ahead of the 179.1% gained by the Technology Select Sector SPDR (NYSEArca: XLK).

In fact, financials are closing in on tech for the top spot. “The sectors that have gained ground in 2013 include Financials, Health Care, Consumer Discretionary and Industrials.  Energy, Consumer Staples, Materials, Utilities and Telecom have all lost ground,” according to Bespoke Investment Group.