Shares of Samyang Foods have been on the boil, up 265% over the past year, fueled by the raging popularity of its spicy Buldak (fire chicken in Korean) instant noodles.

which began in 2014 and involves YouTubers trying to finish an entire serving of Samyang’s Buldak-Bokkeum-Myeon aka Korean Fire Noodles, which roughly translates to “hot stir-fried chicken ...