Mistral, a Paris-based startup developing artificial intelligence that is open source, has been speaking to investors about raising several hundred million dollars at a valuation of $5 billion, according to a person with direct knowledge. The company, which has just recently begun to generate revenue, in December raised $415 million at a valuation of $2 billion.The possible back-to-back financing reflects investors’ continued appetite for certain AI startups and the large amount of capital such ...