Billionaire investor Bill Ackman says he wouldn't trust Russian banks after SWIFT sanctions – as bank runs begin in Moscow

Bill Ackman warned that Russia's banks could be in trouble after the US and its allies imposed tough new sanctions.

The US, the EU, the UK and Canada over the weekend said they would cut select Russian banks out of a key global payments messaging system. Analysts said that the move could wreak havoc on Russia's financial system.

Ackman said on the weekend that he wouldn't want to keep money in a bank that can't access the SWIFT system.

Once a bank cannot transfer or receive funds from other banks, its solvency can be at risk. I would take my money out now if I were a Russian. Bank runs could start in Russia on Monday.

There were signs that bank runs could start on Saturday. News agencies reported long lines at ATMs in Moscow and other cities as people tried to withdraw foreign currency from banks, fearing that the Russian ruble could collapse.

It was too early to tell if the situation would turn into a bank run in which financial institutions run out of money.

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Russia's invasion of Ukraine could be the biggest war in Europe since 1945. Western countries are trying to cripple the country's financial system.

The ruble was down 20% on Monday morning. The central bank more than doubled interest rates to try to lure capital back into the country and encourage people to keep their money in the banks after it dropped more than 30%.

Russia's economy is at risk from sanctions and a tumbling currency, analysts said.

Jorg Kraemer of Commerzbank said that the pressure on the system would be increased if banks were banned from SWIFT.

Neil Shearing, chief economist at Capital Economics, said that all of this will accelerate Russia's economic downturn.

Ackman is a well-known investor. He suggested the US military should get involved in the Russia-Ukraine conflict on Monday.

Insider is covering developments as they happen.