Chinese frontier artificial intelligence start-up DeepSeek is in talks with investors to raise a new financing round at around US$70 billion pre-investment valuation, shortly after closing a landmark first round, reflecting unquenched investor enthusiasm for the company.The plan comes on the heels of the Chinese AI darling’s recently closed Series A funding round in June – its first external funding round – which brought in about US$7 billion and valued the Hangzhou-based firm at nearly US$60...