In the aftermath of the Orlando massacre, gun retailers say business is booming, particularly with gay and lesbian clientele.

Reports show gun sales spike after mass shootings, but shops say the surge among LGBT members is new, according to KDVR.

“We’re not surprised by it,” George Horne, owner of a Denver firearms dealer, told KDVR.

The Pink Pistols, an international club for gay and lesbian gun owners, report seeing membership jump from around 1,500 members to 3,500 by Monday.

Gwendolyn Patton, first speaker of the club, said the group is working to prevent tragedies such as the one at Pulse Nightclub in Orlando, where alleged gunman Omar Mateen fatally shot 49 people and wounded 53 more. The incident Sunday was the deadliest mass shooting in U.S. history.

“It’s sad that we must consider such things, but when there are persons out there who mean us harm, we must find ways to protect ourselves within the law.” Patton said in a statement.

A Colorado Springs firearms instructor, Mike Smith, who identifies as heterosexual, plans to open a new chapter of the Pink Pistols in Colorado Springs.

“I look at it as a disenfranchised minority that needs someone who’s willing to say I’m a resource who’s here and willing to help,” Smith told KDVR.

Florida gun retailers also had more customers than usual. Robbie Motes, owner of The Armories, a gun retailer with three locations in the Orlando area, told NBC his store typically sells 10 to 15 guns a day, but on the Monday after the shooting it reached that number by noon.

“Today is probably triple a normal day,” Motes said on Monday.

Motes says he has seen this trend after other mass shootings.

“After the tragedy in Sandy Hook, it was astronomical,” he said.

Stocks of major gun manufacturers on Monday spiked. Gun-maker Smith & Wesson’s shares rose 8.5 percent on Monday, while another manufacturer Sturm Ruger increased 6.9 percent, according to CNBC.

“History would suggest the more awful and tragic the event… and as the rhetoric of gun control rises, the stocks go up,” analyst James Hardiman told CNBC.