Why the S.E.C. Didn’t Hit Goldman Sachs Harder

In the late summer of 2009, lawyers at the Securities and Exchange Commission were preparing to bring charges in what they expected would be their first big crackdown coming out of the financial crisis. The investigators had been looking into Goldman Sachs’s mortgage-securities business, and were preparing to take on the bank over a complex deal, known as Abacus, that it had arranged with a hedge fund. They believed that Goldman had committed securities violations in developing Abacus, and were ready to charge the firm.