Why Argan Stock Topped the Market Today

By Eric Volkman – Mar 9, 2026 at 7:36PM ESTKey PointsWith considerable momentum already behind the stock, that isn't likely to have a material effect on investor sentiment.Yet it enhances the company's reputation as an enterprise to watch.Inclusion in a famous family of stock indexes was the fuel propelling Argan's (AGX +12.73%) equity to a double-digit gain on Monday. The industrial construction specialist, already a popular investment thanks to its involvement in artificial intelligence (AI) build-outs of data centers, saw its share price rise by nearly 13% that trading session. One of 600 After market close on Friday, S&P Dow Jones Indices -- a key business unit of financial information and data company S&P Global -- announced a raft of changes to its indexes. Image source: Getty Images. Argan was tapped to join the S&P SmallCap 600 index. It was one of 16 such "graduations" in a class that included stocks such as rideshare company Lyft, dating website operator Match Group, and Sphere Entertainment. Argan, along with most of the others, will formally become an index component before market open on Monday, March 23. ExpandNYSE: AGXArganToday's Change(12.73%) $52.75Current Price$466.95Key Data PointsMarket Cap$5.7BDay's Range$412.52 - $466.9552wk Range$101.02 - $469.88Volume36KAvg Vol365KGross Margin19.08%Dividend Yield0.42% Good timing Despite a third-quarter earnings report that missed the consensus analyst revenue estimate -- and therefore led to a brief sell-off -- Argan's stock has done extremely well lately. It's in the right business at the right time with its AI data center activity, and it should also benefit from the Trump administration's desire to build out American infrastructure. I don't think the S&P SmallCap 600 will make investors any more bullish on the stock than they already are, though it's inarguably a feather in Argan's cap. Read NextFeb 14, 2026 •By Howard SmithWhy Argan Stock Soared This WeekJan 22, 2026 •By Catie HoganThis Could Be One of the Best Industrial Stocks to Hold for the Next 10 YearsDec 5, 2025 •By Eric VolkmanWhy Argan Stock Plummeted by 12% TodayOct 13, 2025 •By Howard SmithWhy Argan Stock Soared TodaySep 10, 2025 •By Eric VolkmanWhy Argan Stock Climbed Higher on WednesdaySep 5, 2025 •By Keith NoonanWhy Argan Stock Is Plummeting TodayAbout the AuthorEric Volkman is a contributing Motley Fool finance and stock market analyst. Previously, Eric was an equities analyst at European investment bank Raiffeisen Capital and Investment. He’s also been a freelance finance writer since 1995. He studied at Susquehanna University.TMFVolkmanStocks MentionedArganNYSE: AGX$466.95(+12.73%)+$52.75S&P GlobalNYSE: SPGI$445.64(-1.49%)-$6.72LyftNASDAQ: LYFT$13.77(+3.89%)+$0.52Match GroupNASDAQ: MTCH$31.15(+2.21%)+$0.68Sphere EntertainmentNYSE: SPHR$117.64(+4.27%)+$4.82*Average returns of all recommendations since inception. Cost basis and return based on previous market day close.