Jeremy Grantham’s firm is taking a very bearish stance on China, believing the country is in a huge infrastructure and real estate bubble.

“China is experiencing the mother of all bubbles,” Peter Chiappinelli, portfolio strategist at Grantham’s GMO, says, according to InvestmentNews.com. “We don’t know when it’s going to pop or what’s going to cause it to pop, but there’s very little track record of countries successfully navigating a soft landing out of a bubble.”

GMO is hedging its China exposure to near zero in the emerging-markets portions of its mutual funds, Chiappinelli said, and it is net short on the country in its hedge fund.