Shares of gun manufacturers fell sharply Friday before erasing some of their losses, as the debate over gun control continued to heat up in the wake of the Feb. 14 school massacre in Florida, and investment funds came under fresh pressure to divest from the sector.

A week after 17 people were killed at a high school in Parkland, Fla., the pressure on Congress to act on guns is building, as students take the lead in pushing for reform at rallies and town halls with politicians.

Stocks had rallied on Thursday after President Donald Trump suggested he would support a move to raise the legal age for buying firearms to 21 from 18. Talk of regulating guns typically spurs a wave of buying, as consumers rush to get in ahead of any change in the law.

But Trump also appeared to endorse a position put forward by the National Rifle Association to arm some teachers, drawing the ire of parents whose children have been victims of attacks, as well as the president of the American Federation of Teachers.

The failure of successive governments to enact reforms after such tragedies as the killing of 20 children at an elementary school in Newtown, Conn., in 2012, and the deaths of more than 50 people at a country-music concert in Las Vegas last year, has come under sharp focus this week.

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Some companies are already rethinking their ties to the NRA. First National Bank of Omaha, the biggest privately owned U.S. bank, and Enterprise Holdings, operator of Alamo Rent a Car and National Car Rental, are among the companies that have said they are ending partnerships with the NRA.

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“This is a bold move for First National of Omaha but also a risky one because passions burn so hot on both sides of the topic of guns,” said Matt Schulz, senior industry analyst at CreditCards.com.

“Many will applaud the move, but NRA members are famously loyal, and the organization has shown itself as being very good at mobilizing its members, so there’s a real possibility of a significant backlash. However, banks are in the business of managing risk of all kinds, and First National clearly sees this as one they’re willing to take in the wake of the tragic school shooting in Florida.”

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Sturm, Ruger & Co. Inc. shares RGR, +0.11% fell as much as 4 % early in the day, before recovering to trade slightly higher. Shares of American Outdoor Brands Corp. US:AOBC , the parent of Smith & Wesson, fell 6% and are now down 48% in the last 12 months.

Vista Outdoor Inc. shares VSTO, -0.21% were down 2% before recouping some of those losses.

Shares of Dick’s Sporting Goods Inc. DKS, -0.20% , which sells guns along with a wide range of sports gear, were down 0.3%. Camping World Holdings Inc. CWH, -2.93% , owner of Gander Outdoors, was up almost 4%.

The S&P 500 SPX, -1.11% was up 1.3% and the Dow Jones Industrial Average DJIA, -0.87% was up 1.1%.

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