Perplexity AI was criticized by Forbes and Wired in recent weeks.Getty/NurPhotoPerplexity AI reportedly secured $500 million in its latest funding round this month.That puts the startup's valuation at $9 billion, tripling its worth within six months.A handful of AI startups have seen its valuation skyrocket amid rapid funding rounds this year.Perplexity AI closed a $500 million funding round earlier this month, pushing its valuation to $9 billion, a source familiar with the matter told Bloomberg.That means the AI search engine startup has managed to triple its valuation within six months after an investment from SoftBank put the company at a $3 billion valuation in June.The latest funding round was led by Institutional Venture Partners, the source told Bloomberg.