Gunmaker stocks took off Monday in the wake of the Orlando massacre.

Smith & Wesson shares were up 6.9 percent, to close at $22.88, boosted by fears of tighter gun control after the deadliest mass shooting in US history.

The stock of Sturm, Ruger & Company, which makes an automatic assault rifle similar to the one used by mass-killer Omar Mateen, rose 8.5 percent, to $62.29 per share.

In the last five large mass murders, Smith & Wesson has averaged a 4.8 percent stock-price gain in the three days following the attacks. Sturm, Ruger averaged a 2.6 percent increase over the same period.

The assault rifle used by Mateen was made by Sig Sauer — a privately held company with headquarters in Newington, NH — and legally purchased at a firearms shop near his Florida home on June 4.

He returned to the store to buy a Glock 17 on June 5.

Mateen’s employer, UK-based G4S, issued a statement Sunday claiming to be “deeply shocked by the tragic events.”

G4S, the world’s biggest security firm, said Mateen had been subjected to “detailed company screening when he was recruited in 2007 and re-screened in 2013 with no adverse findings.” It added

that US law enforcement had also screened Mateen but did not share its results with the company.

G4S shares fell 4.9 percent, to 178.14 pence, in trading Monday on the London Stock Exchange.

The stock has fallen 37 percent during the past year, as G4S seeks to rebuild a reputation sullied by its failure to supply a sufficient number of security guards during the 2012 Olympics in London.