Originally Published: 13 JUN 22 09:31 ET

Updated: 13 JUN 22 10:59 ET

By David Goldman, CNN Business

(CNN) -- US stocks plunged into bear market territory Monday morning as Wall Street investors grew increasingly nervous about the prospect of even more harsh medicine from the Fed to take the sting out of inflation.

The Dow sank 825 points, or 2.7%, and the Nasdaq fell 4.3%.

The broader S&P 500 fell 3.6%. That index is now more than 20% below its all-time high set in January, putting stocks in bear-market territory.

Inflation and recession fears had eased somewhat at the end of May, and stocks regained some ground. But Friday's miserable Consumer Price Index report showed US inflation was significantly higher than economists had expected last month, which could make the Federal Reserve's inflation-control efforts more difficult.

After raising rates by a half point in May — an action the Fed hadn't taken since 2000 — Chair Jerome Powell pledged more of the same until the central bank was satisfied that inflation was under control. At that point, the Fed would resume standard quarter-point hikes, he said.

But after May's hotter-than-expected inflation report, Wall Street is increasingly calling for tougher action from the Fed to keep prices under control. Jefferies joined Barclays on Monday in predicting that the Federal Reserve would hike rates by three-quarters of a percentage point, an action the Fed hasn't taken since 1994.

"After holding their breath for nearly a week awaiting the US CPI report for May, investors exhaled in exasperation as inflation came in hotter than expected," Sam Stovall, chief investment strategist at CFRA, said in a note to clients Monday morning.

Stovall said the risk of larger hikes is dragging the markets lower Monday.

Investors fear two outcomes, neither of them good: Higher rates mean bigger borrowing costs for businesses, which can eat into their bottom lines. And overly zealous action from the Fed could unintentionally plunge the US economy into a recession, especially if businesses start laying off workers and the red-hot housing market crumbles.

There's no sign that the job and housing markets are in danger of collapse, although both are cooling off somewhat.

In an interview with CNN's Fareed Zakaria Sunday, former Fed Chair Ben Bernanke said a US recession remains possible. But Bernanke said he had faith that Powell and the Fed could achieve a so-called soft landing, the elusive outcome in which the central bank can cool the economy down to get inflation under control without slowing it down so much that it enters a recession.

"Economists are very bad at predicting recessions, but I think the Fed has a decent chance — a reasonable chance — of achieving what Powell calls a 'soft-ish landing,' either no recession or a very mild recession to bring inflation down," Bernanke said.

Bears and bulls

If the S&P 500 closes in a bear market, the bull run that started on March 23, 2020 will have come to an end. But, because of the tricky way these things are measured, the bear market will have begun on January 3, when the S&P 500 hit its all-time high.

That would mean the latest bull market lasted just over 21 months — the shortest on record, according to Howard Silverblatt, S&P Dow Jones Indices senior index analyst. Over the past century, bull markets have lasted an average of about 60 months.

The shortest bull market will have followed the shortest bear market, one the lasted just over a month — from February 19 to March 23, 2020. Bear markets historically last an average of 19 months, according to Silverblatt.

Stocks briefly fell into a bear market on May 20, although a late-day rally rescued the market from closing below that threshold for the first time since the early days of the pandemic.

The tech-heavy Nasdaq has been in a bear market for some time and is now 32% below its all-time high set in November 2021. The Dow is still some way off a bear market. It has fallen 15% from the all-time high it reached on the last day of 2021.