A sell-off for stocks wrapped around the world and hit Wall Street yesterday, while oil prices climbed even higher on worries about the widening war with Iran. But the big moves that rocked markets in the morning eased substantially as the day progressed.

By the end of trading, the S&P 500 had sunk 0.9%. That would be a solid loss on a typical day, but the index had been down as much as 2.5% in the morning because of worries that the war may do more sustained damage to the economy than feared.

The Dow Jones Industrial Average dropped 403 points, or 0.8%, after plunging more than 1,200 points earlier in the morning. The Nasdaq composite pared its loss to 1%.

It was just a day earlier that U.S. stocks opened the morning with a sharp loss, only to recover all of it and end the day with a tiny gain. Helping to drive that rebound was a record showing that past wars and conflicts in the Middle East have not usually meant long-term pain for U.S. stocks.

But that was with the caveat that oil prices did not jump too high, like above $100 per barrel. On Tuesday, oil prices rose again and raised more alarms. The price for a barrel of Brent crude, the international standard, briefly leaped above $84.

The jump lessened through the day, though, which helped moderate the losses for stocks. Brent settled at $81.40, up 4.7%. A barrel of benchmark U.S. crude rose 4.7% to $74.56.

The moves showed oil prices, and how much they’re set to worsen inflation, are among the central fears for investors. More expensive fuel will mean less money for U.S. and other households to spend. It would also raise expenses for companies worldwide, which would likewise hurt their profits. And corporate profits are the lifeblood of stock markets.

Tuesday’s climb for oil prices came after Iran struck the U.S. Embassy in Saudi Arabia, part of a widening of targets that also includes areas critical to the world’s oil and natural gas production. Worries are particularly high about the Strait of Hormuz off the coast of Iran, a narrow passageway where roughly a fifth of the world’s oil passes.

Iranian Brig. Gen. Ebrahim Jabbari, an adviser to the paramilitary Revolutionary Guard, vowed that any ships that passed through the strait would be set on fire.

The fears about oil prices ebbed a bit later in the day as President Donald Trump said the U.S. Navy could begin escorting tankers through the strait, “if necessary,” to “ensure the FREE FLOW of ENERGY to the WORLD.”

Making things uncertain for markets is the question about how long this war may continue.