After months of speculation about whether OpenAI or Anthropic would be first in their race to IPO, Anthropic on Monday reached a key milestone: filing to kick off the process with the U.S. Securities and Exchange Commission. The filing sets the stage for what's sure to be a massive IPO. As of its fundraise last week, Anthropic is being called the world's most valuable startup, with a post-money valuation of $965 billion. That tops the $852 billion post-money valuation of OpenAI, which is its big