Looking ahead, the new GICS classification will also further support the REITs sector.

“With the sector carve out of REITs we think asset managers and investors that build portfolios based on the S&P 500 index will focus more on REITs,” Rosenbluth added. “In our opinion, this should help all ETFs that have exposure to these stocks.”

In anticipation of the eventual S&P 500 changes, State Street Global Advisor came out with the Financial services Select Sector SPDR Fund (NYSEArca: XLFS) and the Real Estate Select Sector SPDR Fund (NYSEArca: XLRE) back in October.

XLRE will try to reflect the performance of the Real Estate Select Sector Index, which include real estate management and development and REITs, excluding mortgage REITs. The underlying index has a dividend yield of 3.42%.

XLFS will try to reflect the performance of the Financial Services Select Sector Index, which tracks areas like diversified financial services, insurance, banks, capital markets, consumer finance, thrifts, mortgage finance and mortgage REITs. The underling index has a dividend yield of 2.06%.

Moreover, investors can look to the Guggenheim S&P 500 Equal Weight Real Estate ETF (NYSEArca: EWRE), which follows an equal-weight indexing methodology but also tracks a similar portfolio as XLRE.