Case in point: Gunmakers had one of their best months ever in December, according to an analysis of federal background check data by the New York Times, immediately following the President’s call for tougher assault weapon purchasing measures after the mass shooting in San Bernardino, Calif.

During that month, sales spiked as high as 1.6 million guns sold, leading firearm manufacturers such as Smith & Wesson (SWHC) recently to mark up their revenue projections.

Another one of the industry’s top-performing months followed the President’s gun control-promoting remarks after a mass shooting at Sandy Hook Elementary School in Connecticut in Dec. 2012. By the next month, 2 million guns had been sold, according to the Times. (The data on which the Times’ analysis rests can be found here.)

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“Fear of gun-buying restrictions has been the main driver of spikes in gun sales,” the Times reported, “far surpassing the effects of mass shootings and terrorist attacks alone.” In other words, it’s not just acts of violence, but talk of regulation, that moves the markets.

On Tuesday, the President officially announced his executive actions aimed at reducing gun violence, as he stressed the importance of background checks and expressed his frustration with mass shootings around the country.

Shares of Smith & Wesson and Sturm, Ruger & Company (RGR)—two of the nation’s biggest firearms makers—rallied.

BB&T Capital Markets analyst Brian W. Ruttenbur last month labeled the President “the best salesmen for firearms,” as the Times notes.