The S&P 500 could plummet by another 26% in the next year as financial markets face an unprecedented confluence of challenges. He said he was betting against junk bonds.
"This is a more dangerous looking moment in global economics than the madness of the housing bubble of 2007," he said.
The benchmark US stock index could fall from its December peak of 4,000 points to 3000 points in the next year. The S&P 500 is lower this year.
He said that the decline in fundamental values on a global basis looked shocking.
In a research note published on August 31, Grantham stated that it was entering its final act after sounding the alarm on a "superbubble" in asset prices.
He highlighted the dangerous combination of hugely overvalued stocks, bonds, and housing, as well as soaring inflation and interest-rate shocks. shortages of food and resources, as well as Russia's invasion of Ukraine, are some of the concerns he raised.
There will be a collapse in growth stocks, chaos in global housing markets, and rising mortgage rates, according to a long-term investment strategist.
The stock market was predicted to be under pressure. Climate change is disrupting economies, national workforces are decreasing due to low birth rates, and the worldwide supply of commodities is drying up.
He said that inflation has made a marginal bear market a fairly serious bear market.
He wants to make money from the huge amount of damage he expects. He told The Times in an interview that he has placed bets against the high-yield bonds.
The index has fallen from its peak. The index is seen as riskier and more volatile than the S&P 500 because it has a larger proportion of unprofitable companies.
Credit agencies rate high-yield bonds lower than investment- grade bonds. They are riskier than higher-rated bonds and offer larger yields to investors.
Tech stocks and junk bonds are expected to fall when the superbubble burst, according to a wager made by the investor.
There are 17 fast-growing stocks that are cheaply valued and forging a path to profitability.