Artificial intelligence search company Perplexity has begun fundraising talks in which it is looking to more than double its valuation to $8 billion or more, as startups try to ride the coattails of OpenAI's recent big investment.

Perplexity has raised three rounds of funding in the past year -- an unusually fast pace even by the standards of Silicon Valley. In January, it was valued at $520 million. By this summer, its valuation grew to $3 billion.