2020 Russia–Saudi Arabia oil price war

On 8 March 2020, Saudi Arabia began a price war with Russia, causing a major fall in the price of oil, with US oil prices falling by 34%, crude oil falling by 26%, and brent oil falling by 24%. 
The price war was caused by a breakup between the Organization of the Petroleum Exporting Countries and Russia over proposed oil production cuts due to the 2019–20 coronavirus pandemic. Oil prices had already fallen 30% since the start of the year due to a drop in demand. 
The fall in prices was one of the causes of the global stock market crash on 9 March 2020, which became known as Black Monday.
As demand continued to fall dramatically, oil prices went down further, reaching a 17-year low on 18 March where Brent was priced at $24.72 a barrel and WTI at $20.48 a barrel.
On 30 March 2020, the price of Brent Crude fell 9% to $23 per barrel, the lowest level since November 2002.
On 20 April 2020, Oil prices reached a record low, falling into negative values, due to the ongoing coronavirus pandemic and the Russia–Saudi Arabia oil price war.