If you're nervous about the stock market, you've got good reason to be:  Central banks around the globe are losing the battle against inflation,  and their response could plunge the global economy into a recession.

Step back: Last week, the Federal Reserve hiked interest rates by three-quarters of a percentage point — its biggest rate rise since 1994.

The Bank of England increased its target rate, too, for the fifth time since December. And the Swiss central bank raised rates for the first time in 15 years.

They're hardly done. The BOE conceded that inflation would spike near 11% in the fall, and the Fed just increased its inflation expectations for 2022 by a full percentage point.

Although Fed Chair Jerome Powell said last week there's still a chance  the US economy could avoid recession, he conceded that Russia's invasion  of Ukraine

the ongoing pandemic and the supply chain and energy crunches "have  raised the degree of difficulty and created great challenges ... so we  just don't know."

By pulling back stimulus and putting the monetary policy engine into  full reverse, the Fed and other central banks have rattled investors.

The US stock market has entered a bear market,  and last week was Wall Street's worst since March 2020: The S&P 500  tumbled nearly 6%, and the Dow plummeted 1,504 points, or about 5%.

US stocks have fallen 23% since hitting a record high January 3. Yet  they could have plenty more room to fall — particularly if the efforts  to gain control of runaway prices send the economy into a downturn.

"The Fed may be willing to push the economy into a recession to actually  get inflation under control," Anthony Saglimbene, global market  strategist at Ameriprise, told me.

"I think that was probably in the back of investors' minds, but it's  front and center now. Stocks are going to have a hard time until they  figure out where that end point is for the Fed," he added.