Massive Fraud - this decades Ivan Boesky
 

Although Boesky was small potatoes at $200 million by betting on corporate takeovers using inside information.

From Wikipedia:
He was investigated by the U.S. Securities and Exchange Commission for making investments based on tips received from corporate insiders. These stock acquisitions were sometimes brazen, with massive purchases occurring only a few days before a corporation announced a takeover.



NEW YORK (Reuters) ? Bernard Madoff, a quiet force on Wall Street for decades, was arrested and charged on Thursday with allegedly running a $50 billion "Ponzi scheme" in what may rank among the biggest fraud cases ever. more

1 billion was all he need