Oil prices tumbled as much as 34% — the most in decades — between Sunday and Monday.

In later trading, prices stabilized to about a 20% decline.

The Dow Jones Industrial Average and S&P 500 indices both slumped around 7% in mid-day trading on Monday. Earlier in the session, sharp losses prompted a trading halt.

The dramatic plunge was prompted by Saudi Arabia, which sharply cut prices. It was a response to Russia, which over the weekend refused to restrict how much oil it was producing.

This was the biggest single-day drop since the Gulf War in 1991.

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The price of oil tumbled more than 30% on Monday, its sharpest single-day decline since the Gulf War in 1991.

The price recovered somewhat after that initial fall and was trading about 20% around mid-day.

At their lowest, oil prices were down 34%.

Here's where trading stood as of 1:50 p.m. ET

Brent crude was trading at $36.12 a barrel — down about 20%.

West Texas intermediate was trading at $32.98 a barrel — down about 20%.

The Dow Jones industrial average was down 1,847.88 points — a drop of 7.1%.

The S&P 500 was down 204 points — a drop of 3.6%.

The UK FTSE 100 was down about 497 points — a drop of 7.7%.

The crash was fueled by sinking demand amid the worldwide spread of the novel coronavirus, which in turn sparked a series of price cuts.

Saudi Arabia started the price wars by cutting prices by its most in at least 20 years over the weekend, retaliation after a dispute with Russia on Friday over how much to restrict production.

At a meeting in Vienna, Saudi officials asked Russia to cut back on production, hoping to keep the price higher during the outbreak.

Russia refused. As a result, the Saudis cut their prices, effectively launching three-way price war between the OPEC oil-producing alliance (led by Saudi Arabia), Russia, and the US.

Goldman Sachs analysts have warned that the price of oil could tumble further still, as low as $20 a barrel.

The prices of oil companies were also down, with BP shares experiencing price drops of as much as 20% and Shell of 14%.

Markets and assets across the board were also hit hard by the crash, Business Insider's Theron Mohamed reported.