Bloomberg Opinion columnist Barry Ritholtz interviews John Carreyrou, the Pulitzer-winning investigative reporter who exposed wrongdoing at the much-hyped startup Theranos. Its founder was recently charged with "massive fraud" by the SEC. Carreyrou has been awarded the George Polk Award for Financial Reporting, the Gerald Loeb Award for Distinguished Business and Financial Journalism, and the Barlett & Steele Award for Investigative Journalism. His new book is "Bad Blood: Secrets and Lies in a Silicon Valley Startup."