Finance

In 1995, a trader who hid losses in a secret account and kept making reckless trades bankrupted 232-year-old Barings Bank of Britain. His losses totaled £827 million—twice the bank's capital—and the Netherlands ING Group acquired it for just £1.

The "Rule of 72" lets you quickly estimate compound interest. Divide 72 by the interest rate to find how many years it takes to double your money. At 6% annual return, 72 ÷ 6 ≈ 12 years to double. The actual result is 2.012×—remarkably accurate.