“The large tech companies already have low effective tax rates because they were gaming the system,” Michael O’Rourke, chief market strategist at JonesTrading Institutional Services LLC, told Bloomberg. “Any reform would have to close the loopholes, which obviously they’re trying to do, so they don’t benefit.”

U.S. equities started off the day on speculation that the Senate would pass cuts to corporate taxes, with the financial segment leading on bets that banks would benefit the most.

Some observers view the sudden shift as a catalyst for a sector rotation play.

“It’s surprising that you’re seeing a pullback this big after such a strong fundamental performance,” Mike Bailey, director of research at FBB Capital Partners, told CNBC, noting that tech earnings have been strong. “I do wonder if there is some rotation going on. The banks’ story is getting better after Jerome Powell’s testimony.”

For more information on the tech segment, visit our technology category.