** HK shares of Xpeng 9868.HK jump 9.5% to HK$86.25; set for biggest one-day pct rise since February 4

** Stock hits highest since March 24; top pct gainer on Hang Seng Tech Index .HSTECH, which is up 1%

** U.S.-listed stock XPEV.N climbed 5.2% on Monday

** Chinese smart EV maker's March delivery soars 268% y/y; 2025 Q1 delivery shoots 331% y/y

** YTD, HK stock gains 82.3%, U.S. shares up 75.3%

(Reporting by Donny Kwok)

((donny.kwok@thomsonreuters.com))