After the close of U.S. markets Monday, S&P Dow Jones Indices and MSCI (NYSE: MSCI), two of the largest providers of benchmarks for exchange traded funds, announced that real estate will become the eleventh Global Industry Classification Standard (GICS) sector.

“Feedback from the annual GICS structural review confirmed that Real Estate is now viewed as a distinct asset class and is increasingly being incorporated separately into the strategic asset allocation of asset owners,” said Remy Briand, managing director and global head of equity research at MSCI, in a statement. “Investors told us that there are significant differences between public Real Estate and Financial companies and therefore Real Estate deserves a dedicated GICS Sector.”

The change is not imminent (it is slated to occur after markets close on Aug. 31, 2016), but ETF and indexing nerds are apt to have some fun speculating on how real estate’s ascent to the eleventh GICS sector will affect ETFs.

For now, assessing the changes real estate’s sector status will have on indices and ETFs means working in hypotheticals. In its current form, which includes real estate, financial services is the S&P 500’s second-largest sector weight at 16.5%, about 300 basis points behind technology.

There are about 20 real estate investment trusts (REITs) in the S&P 500, indicating that if real estate were to become the eleventh sector in the coming weeks, which is not happening, the group’s departure from financial services could relegate that sector to third-largest behind tech and health care.

The largest REIT in the S&P 500 is Simon Property Group (NYSE: SPG), but at a weight of just about a third of percent, over 80 stocks have larger weights in the benchmark U.S. index than Simon Property does. In its current form, the real estate sector would likely be left fighting with materials, utilities and telecom as one of the four smallest S&P 500 sector weights. [Investors Flock to REIT ETFs]

Materials, utilities and telecom currently combine for 9% of the SPDR S&P 500 ETF (NYSEArca: SPY).

Predictably, dedicated financial services ETFs will be most affected by real estate becoming its own sector. The largest ETF tracking the financial services sector, the Financial Select Sector SPDR (NYSEArca: XLF), currently allocates 14.1% of its weight to REITs and another 0.3% to real estate management and development firms.