CNBC reports that Famed investor Jeremy Grantham reiterated his warning that Wall Street is in a bubble as individual traders get “carried away.”

“They’re becoming euphoric … They’re borrowing money. They’re trading more shares,” Grantham, co-founder and chief investment strategist at Grantham, Mayo, & van Otterloo told CNBC.

In recent months, Grantham has warned that the massive runs on Wall Street are turning into an “epic bubble.” 

On Thursday, Grantham pointed to the number of over-the-counter shares traded since last February rocketing to 280 million shares in November and quadrupling to 1.15 trillion shares in December.

“We have very seldom seen levels of investor euphoria like this,” he said, referring to individual investor speculation, rather than institutional.