Lisa Caso sells guns at Caso's Gun-A-Rama store during late March in Jersey City, N.J. The store has seen a recent spike in business as people fear there will be increased gun control following recent mass shootings and under the Biden administration.

Gunmakers Sturm Ruger and Smith & Wesson rose last week after the FBI’s National Instant Criminal Background Check System showed U.S. unadjusted criminal background checks rose 25% to a record in March from a year ago.

Unadjusted checks climbed to 4.69 million last month from 3.74 million in March 2020, and gained 36% from 3.44 million in February.

Six days in March made the list of the top 10 highest days for background checks since 1998.

The week of March 15 to 21 set a new all-time record while the week of March 22 was fourth best.

After the report on the high levels of background checks came out on Thursday, stock values for gunmakers went up.

Sturm Ruger climbed as much as 2.8%, while Smith & Wesson added 3.8%.

While gun sales aren’t tracked in the U.S., NICS data is considered a proxy for sales by the firearms industry. A background check doesn’t mean a gun sale necessarily occurred.