"It's reasonable for markets to start repricing a possibility of higher inflation and higher interest rates", Sturkenboom said.
In Canada, the S&P/TSX composite index was down 48.73 points to 15,393.95 in a largely broad-based decline.
Stocks were higher earlier in the day after Powell appeared to calm one of the market's main worries when he said that he does not see inflation in workers' wages "at a point of acceleration".
Stocks wavered as investors dissected Federal Reserve Chairman Jerome Powell's latest comments for clues about the future path of interest rates. For the month, the Dow fell 4.3% while the S&P shed 3.9% and the Nasdaq lost 1.9%.
Best Buy has been one of the best performing retail stocks over the last few years.
The blue chip index lost 380 points, or 1.5%, while the S&P 500 lost 1.1%, or 30 points, and the tech-heavy Nasdaq declined by 0.8%, or 57 points.
The Cboe Volatility Index.VIX, the most widely followed barometer of expected near-term volatility of the S&P 500 index .SPX, closed up 1.26 at 19.85, its highest close in a week.More news: North Korea: US military drills harm reconciliation
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Ryan Detrick, senior market strategist at LPL Financial, notes that over the 10- and 20-year periods March and April are the two strongest months of the year. Some investors took that as a signal that the Fed may get more aggressive on rate increases, which sent stocks down and Treasury yields higher.
"The [Federal Open Market Committee] will continue to strike a balance between avoiding an overheating economy and bringing ... price inflation to 2 per cent on a sustained basis", Mr Powell said. The index is coming off its worst month in two years, when concerns about higher inflation and rates helped trigger a 10 percent drop.
Dental products supplier Patterson Companies plunged 23 percent in the first few minutes of trading Thursday after issuing weak quarterly results. Benchmark U.S. crude fell 65 cents to settle at $60.99 per barrel. Brent crude, the worldwide standard, lost 62 cents to $64.11 per barrel.
On the commodities front, oil has dropped slightly and gold is also down.
The dollar fell to 105.54 Japanese yen from 106.24 yen late Thursday. The FTSE 100 in London gave up 1.5 per cent. The euro rose to $1.2331 from $1.2255, and the British pound rose to $1.3790 from $1.3768.
Japan's Nikkei 225 declined 1.39%.