Russia's biggest bank plunges 77% while the ruble hits a record low, as sanctions threaten to cripple the country's economy

• Shares in Russia's biggest bank Sberbank fell as much as 77% in London on Monday, while the ruble hit a new low.
• The losses came after Western allies imposed tough sanctions designed to all but cut Russia out of the global financial system.

Shares in Russia's biggest bank Sberbank plunged almost 80% Monday, and the ruble crashed to a record low as Western sanctions threatened to cripple the country's financial system and economy.

On Monday, Russia's central bank ordered Moscow's stock exchange to stay closed and restricted the selling of assets, in an effort to halt the collapse in prices that began when the country invaded Ukraine last week.

But London-listed Russian companies couldn't escape the pain.

Sberbank's depositary receipts, which represent shares and are traded in London, crashed as much as 77% on Monday morning, according to Bloomberg data. They have since pared losses slightly to trade 65% lower.

The shares have lost 90% of their value since the start of the year, falling from $16.09 to around $1.60 Monday.

Another major Russian bank, Tinkoff, saw its shares plummet more than 80% in early trading Monday in London, before also recovering ground somewhat.

Meanwhile, Russia's currency, the ruble, cratered roughly 30% to a record low against the dollar, before rebounding slightly. It was trading at around 101 rubles per dollar Monday, having started the year at roughly 75, according to Bloomberg data.

The dramatic drops in Russian assets, which followed sharp falls last week, came after the US and its allies ramped up sanctions on Russia over its invasion of Ukraine.

Europe and Canada joined the US in cutting certain Russian banks' access to the SWIFT system, a crucial piece of financial infrastructure that underpins global payments.

The group also imposed measures on Russia's central bank, in an effort to limit its ability to offset sanctions by using its more than $600 billion stockpile of reserves.

"Asset markets were shocked by the comprehensive scale of new sanctions against Russia that were implemented over the weekend," said Peter Garnry, head of equity strategy at Saxo Bank. "The new measures will cripple the Russian financial system."

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Germany's largest stock exchange operator, Deutsche Boerse, on Monday halted trading in 16 Russian securities, including Sberbank, airline Aeroflot and energy companies Gazprom and Rosneft.

Gazprom dropped as much as 60% in London, however. Investors were also reacting to the actions by sports authorities and teams to cut ties with Gazprom and other Russian companies.

Russia's central bank more than doubled interest rates Monday to 20% as it tried to arrest the decline in the ruble. Higher rates traditionally can make investment in a country more attractive, potentially boosting the currency.

The sanctions have spooked many Russians, who have lined up to withdraw foreign currency from ATMs due to fears that the ruble could plunge further, according to news agencies.

The European Central Bank said Monday that several European units of Sberbank were failing or likely to fail after customers rushed to withdrew money as a result of the war.

Russian bonds have also been hit hard as investors have slashed their exposure to the country's debt. The market value of 10 of the biggest and most liquid dollar-denominated Russian bonds fell 26% or $8.8 billion last week, according to Bloomberg data.

Insider's live blog of the invasion is covering developments as they happen.