Jeremy Grantham calls this one of the 'great bubbles of financial history'

Renowned investment manager Jeremy Grantham poses on a balcony at his Rowes Wharf office in Boston.
Lane Turner | The Boston Globe via Getty Images

The party's over on Wall Street as the stock market's massive runup since 2009 has now turned into a "fully fledged epic bubble," billionaire investor Jeremy Grantham said.

The S&P 500 has skyrocketed nearly 450% since its financial crisis closing low on March 9, 2009, reaching levels not before seen.

Between 2009 and 2020, the broader-market index posted annual gains on nine occasions, including three years of returns greater than 20%. In 2020, the S&P 500 recovered from a drop of more than 30% to end the year up 16.3%, trading at an all-time high.