Oil floats on water. That is the entire secret. A ninth grader could tell you. And Anthony "Tino" De Angelis built one of the largest frauds in American history on it. Fill a sixty-foot storage tank with seawater. Float a thin layer of vegetable oil on top. An inspector drops a measuring line, pulls it up coated in oil, and certifies a full tank. He isn't lying. He saw oil. From a leased tank farm in Bayonne, New Jersey, De Angelis borrowed against inventory that did not exist, using warehouse receipts issued by a subsidiary of American Express. Fifty-one financial institutions lent against that paper, including Bank of America and Chase Manhattan. At the peak, his receipts accounted for more soybean oil than the U.S. Department of Agriculture said existed in the entire country. Nobody ran that check. In this episode:

• The federal school lunc ...