NEW YORK, June 21 (Xinhua) -- U.S. stocks extended losses on Wednesday as investors weighed Federal Reserve Chairman Jerome Powell's testimony before Congress.

The Dow Jones Industrial Average fell 102.35 points, or 0.30 percent, to 33,951.52. The S&P 500 lost 23.02 points, or 0.52 percent, to 4,365.69. The Nasdaq Composite Index shed 165.10 points, or 1.21 percent, to 13,502.20.

Six of the 11 primary S&P 500 sectors ended in green, with energy and utilities leading the gainers by rising 0.92 percent and 0.84 percent, respectively. Meanwhile, technology and communication services led the laggards by losing 1.41 percent and 1.36 percent, respectively.

U.S. stocks fell on Wednesday as investors took a breather from last week's rally that sent the market to levels not seen in more than a year, and weighed Powell's latest comments on monetary policy.

During his testimony before the House Financial Services Committee on Wednesday, Powell said that more rate hikes are likely ahead as the Fed tries to slow U.S. growth and contain price pressures, even though it held rates steady at its policy meeting last week.

It may make sense to continue moving rates higher by the end of the year, but at a more moderate pace, and the timing of additional hikes will be data-dependent, according to Powell. The Fed chief will also testify before the U.S. Senate Committee on Banking, Housing and Urban Affairs on Thursday.

U.S. stocks declined as Powell's testimony to the House affirmed the Fed's threat of higher rates to combat inflation. Wall Street should not have been surprised by Powell's commitment to vanquish inflation, but swap futures are still only pricing in one more rate hike, said Edward Moya, senior market analyst at OANDA, a supplier of online multi-asset trading services.

"The Fed is clearly not nearing the end of its tightening cycle and if other central banks seem poised to deliver more than a couple rate hikes, that might make it easier for the Fed to remain aggressive with tightening. Powell said lowering inflation has a long way to go and that could very well mean that they won't stop until the fall," said Moya.

Meanwhile, technology stocks dragged the three major U.S. indexes downward on Wednesday. Nvidia stock, which has increased nearly 200 percent this year, slid 1.74 percent. Shares of Alphabet and Netflix each fell by more than 2 percent. Tesla stock sank 5.5 percent, its steepest loss in two months, following a downgrade by Wall Street.