Character.AI, a 16-month-old start-up that builds online chatbots, said on Thursday that it had raised $150 million in a recent funding round that valued the company at $1 billion.Character.AI is among a tiny group of small companies — along with the tech industry’s giants — that are building technology that could one day rival the systems under development at OpenAI, the San Francisco start-up that incited the artificial intelligence boom with the release of the online chatbot ChatGPT.These companies have an unusual blend of experienced researchers and outsize ambition, and they require huge amounts of capital. Many experts believe that a handful of companies could dominate work on the new artificial intelligence.“One of the concerns I have is that it will be a winner-take-all or a winner-take-most market — that a few big players will really dominate,” said Erik Brynjolfsson, a Stanford University economics professor and a senior fellow at the school’s Institute for Human-Centered AI.Venture capitalists are joc …
