A shooting at an elementary school in Uvalde, Texas, on Tuesday left at least 21 people dead.
The stock prices of the top 5 US gun- and ammo-makers rose in early trading on Wednesday.
Fear of gun control prompts Americans to stock up on guns and ammo, boosting manufacturers.
The stock prices of America's five largest public gun- and ammunition-makers rose on Wednesday morning after a school shooting on Tuesday in Uvalde, Texas, left 19 children and 2 adults dead.
At 10:15 a.m. ET, Sturm, Ruger & Company, the largest public US gunmaker by value, was up 2.3%, with Smith & Wesson Brands, the second-largest, up 7.2%.
Americans tend to stock up on guns and ammunition when gun control returns to the political agenda. The stock prices of gun- and ammo-makers rose after the 2012 massacre at Sandy Hook Elementary School and the San Bernardino shooting in 2015.
In an address to the nation on Tuesday, President Joe Biden said, "As a nation, we have to ask: When in God's name are we going to stand up to the gun lobby?"
At 10:15 a.m., the ammunition-makers Vista Outdoor, Ammo Inc., and Olin Corporation were respectively up 5.4%, 4.2%, and 0.7%.
Tuesday's massacre at Robb Elementary School in Uvalde was the second-deadliest shooting at a US elementary school, after Sandy Hook in 2012.
Authorities said on Tuesday that the Uvalde gunman bought two rifles and 375 rounds of ammunition in the days following his 18th birthday. The guns and ammunition were bought legally in Texas, which allows people to purchase long guns, such as rifles, from the age of 18.
The National Rifle Association, America's most prominent pro-gun lobby group, is set to host its annual meeting this weekend in Houston. Texas Gov. Greg Abbott and US Sens. Ted Cruz and John Cornyn are slated to speak.
After the Sandy Hook and San Bernardino massacres, President Barack Obama called on Congress to pass tighter gun-control laws.