John Carreyrou is an author and journalist. He is known for having exposed the company Theranos to be a fraud.Carreyrou has reported for the The Wall Street Journal and has been based in Brussels, Paris, and New York City.Carreyrou began his career at the Dow Jones Newswires. He later joined The Wall Street Journal Europe at Brussels, then moved to Paris, then was appointed the deputy bureau chief for Southern Europe, then the bureau chief of the health and science bureau in New York. He has won the Pulitzer Prize twice.Carreyrou was raised in Paris. He received his B.A. in political science and government from Duke University.