It’s been a tough month for fact-checking. After the Rolling Stone campus rape story unraveled, readers of all publications can be forgiven for questioning the process by which Americans get our news. And now it turns out that another blockbuster story is—to quote its subject in an exclusive Observer interview—”not true.”

Monday’s edition of New York magazine includes an irresistible story about a Stuyvesant High senior named Mohammed Islam who had made a fortune investing in the stock market. Reporter Jessica Pressler wrote regarding the precise number, “Though he is shy about the $72 million number, he confirmed his net worth is in the ‘high eight figures.’ ” The New York Post followed up with a story of its own, with the fat figure playing a key role in the headline: “High school student scores $72M playing the stock market.”

And now it turns out, the real number is … zero.

In an exclusive interview with Mr. Islam and his friend Damir Tulemaganbetov, who also featured heavily in the New York story, the baby-faced boys who dress in suits with tie clips came clean. Swept up in a tide of media adulation, they made the whole thing up.