Marc Ostrofsky, who invested and lost $150,000 in American blood-testing startup Theranos, is auctioning his stock certificate for 500,000 shares as an NFT (non-fungible token). The certificate is signed by Theranos' Founder Elizabeth Holmes, who has been accused of fraud. "I may be the only investor to make money off of Theranos when all is said and done," Ostrofsky said.