The grim predictability of stock-market reactions to U.S. mass shootings continued Monday in the wake of a Las Vegas attack that killed at least 59 and wounded more than 500.

Historically, gun stocks have experienced a bump after a mass shooting for reasons both political and emotional. Gun sales typically rise over concerns that a deadly event could lead to more stringent gun-control legislation. Some consumers purchase guns to defend against future attacks.

As news of the attack spread this morning, firearm-related stocks began to rise. Olin Corp., the maker of Winchester ammunition, rose almost 6 percent by midday. American Outdoor Brands Corp., formerly Smith & Wesson Holding Corp., was up about 4 percent and Sturm Ruger & Co. rose 4 percent.

In the past, gun rights supporters and organizations such as the National Rifle Association have warned of future regulatory efforts Democratic administrations may try to impose using a mass shooting as justification. Things could turn out differently, however, now that Republicans control the White House and both houses of Congress.

Political change can have an adverse effect on gun stocks, too. After the 2016 election of Donald Trump, who has espoused less-strict gun control policies than those of his Democratic predecessor, gun stocks sank. American Outdoor Brands has seen its stock decline in the months since the presidential election.