Related: Why Investors Should Reconsider Value ETFs

“This is a huge deal,” Todd Rosenbluth, director of ETF and mutual fund research at CFRA, told Reuters. “Where a stock ends up and who it’s compared to can impact where money goes within capital markets.”

Compared with the real estate spinout, “this is more significant, because it’s impacting more sectors, and the stocks inside these indexes are more widely held,” Rosenbluth told Bloomberg.

ETF investors aren’t strangers to major shifts in the sector and broad index-related ETFs. S&P recently seperated real estate investment trusts from the broader financial sector and formed the newly created S&P 500 REITs Sector. To maintain continuity for ETF investors, ETF sponsors issued a special dividend to investors.

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