1341 GMT - European AI-related stocks trade in the green after opening the day down, as Nvidia's record stock buyback helps sentiment. Nvidia added $150 billion to its existing share-repurchase program, lifting it to $235 billion--the largest buyback in history. ASML shares add 1.8% after trading around 1.2% lower earlier in the session. Chip makers Infineon and STMicroelectronics also rally to rise 3% and 3.4%, respectively. Stocks linked to the build-out in AI data centers also gain, with Siemens Energy and Prysmian up 1.1% and 0.9%, respectively.