The Federal Reserve raised its benchmark rate by half a point on Wednesday, but Chairman Powell said it wouldn't be followed by bigger increases.
He said that a 75-basis-point increase is not something the committee is considering.
The Fed hiked its key rate by 50 basis points, marking the biggest increase since 2000. Benchmark rates will go up to a range of 0.75%-1%, adding to the Fed's quarter-point increase in March that kicked off the first tightening cycle in four years.
The central bank plans to reduce its balance sheet by $95 billion a month.
The US indexes closed at 4:00 pm on Wednesday.
In March, consumer price inflation increased to 8.5%, the highest rate since 1981 and policymakers are stepping up their efforts to cool the economy.
Wall Street is worried that the Fed can engineer a soft landing that doesn't sink the economy, which has shown evidence of strain recently.
Private employers in the US added 247,000 jobs in April, less than the 395,000 expected by economists, according to a report by the private payrolls company. The smallest monthly gain since August was recorded in April.
The war in Ukraine poses a bigger risk to the global economy than higher interest rates do, according to Jamie Dimon.
Research firm Vanda said that retail traders have been plowing less money into US equities, and that the slowdown in investment could last through part of this summer.
The European Union unveiled a proposal that would phase out imports of Russian crude in six months. Hungary will block the ban unless it gets an exception.
The price of West Texas Intermediate crude jumped to $107.33 per barrel. The international benchmark for crude oil surged 5.2% to $110.41.
It was the worst single day drop in the company's history, plunging more than 30%.
The price of gold was $1,883.60 per ounce. After climbing back above 3%, the 10-year yield dropped 3 basis points to 2.93%.
There was a 5.9% gain in the price of the digital currency.