NEW YORK (AP) — Stocks fell sharply Thursday, and oil prices rose as doubt took over again from hope on Wall Street about a possible end to the war with Iran.

The S&P 500 slumped 1.7% for its worst day since January and is back on track for a fifth straight losing week. That stretches back to before the Iran war began, and it would be the longest such losing streak in nearly four years.

The Dow Jones Industrial Average dropped 469 points, or 1%, and the Nasdaq composite sank 2.4% to fall more than 10% below its all-time high set early this year. That’s a steep enough drop that professional investors have a name for it: a “correction.”

Stock markets likewise tumbled across much of Asia and Europe. They’re the latest flip – flops for financial markets in a week that began with big hopes after President Donald Trump said productive talks had taken place about ending the war. But Iran denied direct talks were underway and then dismissed a U.S. proposal for a ceasefire that was delivered via Pakistan.

On Thursday, the fighting continued, and thousands more U.S. troops neared the region. Iran, meanwhile, tightened its grip on the crucial Strait of Hormuz. It may be creating something like a “toll booth” for tankers to get past the narrow waterway, which typically sees a fifth of the world’s oil exit the Persian Gulf through it to customers worldwide.

The price for a barrel of Brent crude oil climbed 4.8% to settle at $101.89 as hopes dimmed for a potential return to normal for the strait. That’s up from roughly $70 before the war began. Benchmark U.S. crude rose 4.6% to $94.48 per barrel.