The South Sea Bubble ruined fortunes — including Isaac Newton's

By 1720, England was seized by South Sea Company fever. The company had taken on great chunks of the national debt in exchange for trading rights, and its shares rocketed as speculators piled in. In a few delirious months the price multiplied roughly eightfold.

Among the early investors was Isaac Newton — Master of the Mint, the greatest scientist alive. He played it smart at first, buying in and then selling out in April with a tidy profit of around £20,000, a fortune at the time. He had seen the prices reaching levels he considered absurd.

Then he watched the shares keep climbing without him.

He could calculate the motions of the heavenly bodies, but not the madness of people.

That line is the one Newton is famously said to have uttered. Unable to bear missing out, he bought back in near the peak — and was still heavily invested when the bubble burst that autumn. The stock collapsed, and Newton lost all his early gains and a great deal more, his net worth falling from over £30,000 to roughly £20,000.

Historians caution that the exact figures and the famous quote are partly anecdote. But one scholarly study concludes the colorful story was largely correct: the man who unlocked gravity was undone by greed, and reportedly couldn’t stand to hear the South Sea mentioned for the rest of his life.