Shares of gun and ammunition makers rallied toward multi-year highs Tuesday, as polls continue to show Joe Biden building a lead over President Donald Trump in a number of swing states. Analysts have said the regulatory environment is among the biggest drivers of demand for guns, as fears of tighter regulations have boosted sales in the past. "Biden's swing-state lead, if it is maintained, provides numerous paths to an election win," Paul Christopher, head of global market strategy at Wells Fargo wrote in a note to clients. The latest Federal Bureau of Investigation data on firearm background checks for May rose more than 30% from a year ago to top the 3 million mark for just the third time since the FBI started providing the data in late-1998, and two months after the monthly record was reached in March. Shares of Sturm Ruger & Co. /zigman2/quotes/200036418/composite RGR -0.37% rallied 4.1% toward the highest close since March 2016 and Smith & Wesson Brands Inc. /zigman2/quotes/202273249/composite SWBI -3.02% hiked up 5.5% toward the highest close since July 2017. Ammunition maker Vista Outdoor Inc.'s stock /zigman2/quotes/205852373/composite VSTO -1.19% rose 1.9% toward the highest close since October 2018. Those stocks have bounced sharply off multi-year lows hit late last year, which followed long downtrends Trump's victory in the November 2016 election eased concerns over potential tighter regulations.