The anecdote highlights how professionals were caught off guard by the AI fervor that swept over the market this year.
Stock prices are also hampered by the growing attractiveness of fixed income reteurns.
"They have hardly gotten anything right since Alan Greenspan first arrived," Grantham said of the Fed.
The Princeton University economist also said there is no chance the Fed raises its inflation target.
The 84-year-old money manager figures the index's year-end value should be about 3,200.
We've gone from TINA-"There Is No Alternative" to stocks, to BARB-"Bonds ARe Back," the BlackRock strategist said.
A decade of 5% inflation might be the least painful way to deleverage the economy, said Vincent Deluard of StoneX Financial.
The billionaire says the banking system is now more equipped to handle a downturn in U.S. home prices.
"I don't think we need a recession to get inflation back in," economist Mark Zandi said.
The key is to look at credit risk instead of what economists say, a strategist says.