On Monday, the ruble hit a new low of less than one US cent as Western nations tightened sanctions against Russia by preventing some of its banks from using the SWIFT global payments system.

In Asia, stocks were neutral, but U.S. and European futures were considerably down as Russian President Vladimir Putin ratcheted up tensions by ordering nuclear troops to be placed on high alert.

Given the possible impact on inflation, energy supply, and other economic implications, markets have swung violently in response to Russia’s invasion of Ukraine.

Putin ordered Russian nuclear weapons to be primed for heightened readiness to fire on Sunday, escalating tensions with Europe and the United States and reawakening Cold War concerns.

Over the weekend, Japan joined efforts by the United States and other Western governments to impose sanctions on Russia, including limits on access to the SWIFT system for select Russian institutions.

Access to the Kremlin’s more than $600 billion in reserves is being restricted by central banks, limiting Russia’s capacity to sustain the currency as it falls in value.

Early Monday, the ruble was trading at 105.27 to the dollar, down from approximately 84 rubles to the dollar on Friday. Sanctions issued earlier had pushed its currency to its lowest level ever against the dollar, and the stock market experienced its worst week ever.

The end of the month generally delivers a slew of economic statistics, but for the time being, the war is taking precedence over other concerns.

In a statement, Jeffrey Halley of Oanda stated, “It’s all about the Russia-Ukraine scenario, and changes in that situation will influence market mood and direction.”

“President Putin will now have to recognize that the ‘Western’ nations are willing to suffer a significant amount of economic hardship in order to punish Russia,” he added.

The S&P 500 futures contract plummeted 2.5 percent, while the Dow industrials futures contract sank 1.6 percent. The DAX futures in Germany fell 3.2 percent, while the FTSE 100 futures fell 1.3 percent.

Asia’s markets looked to be reacting more calmly to the recent developments.

The Nikkei 225 index of Japan rebounded from previous losses to close at 26,514.79. Hong Kong’s Hang Seng Index fell 0.8 percent to 22,584.17. At 3,449.52, the Shanghai Composite index was down 0.1 percent. The Kospi in Seoul increased by 0.6 percent to 2,690.28, while the S&P/ASX 200 in Sydney increased by 0.7 percent to 7,049.10.

Although the battle in Ukraine is unlikely to have a direct impact on Asia, increasing energy costs are an unwanted burden for oil-importing countries like Japan, which is still recovering from the epidemic.

BP said on Sunday that it was selling its 19.75 percent stake in Rosneft, a state-controlled Russian oil and gas corporation, which it has owned since 2013. The current market value of the holding is $14 billion.

Oil prices rose sharply on Monday, with U.S. benchmark oil trading at $96.92 a barrel, up $5.33, or 5.8%, in electronic trading on the New York Mercantile Exchange. On Friday, it fell $1.22 to 91.59 per barrel.

Brent crude rose $4.31 to $98.33 per barrel, gaining 5.6 percent and closing in on the $100 per barrel mark, which it had broken last week.

The S&P 500 rose 2.2 percent to 4,384.65 on Friday, marking its first weekly increase in three weeks. The Dow Jones Industrial Average increased by 2.5 percent to 34,058.75 points. After fluctuating between moderate gains and losses, the Nasdaq composite rose 1.6 percent to 13,694.62. The Russell 2000 index increased by 2.3 percent to 2,040.923 points.

The Ukraine crisis has added to existing concerns about interest rates and inflation.

The Federal Reserve of the United States has hinted that it would raise short-term interest rates next month by twice as much as normal, marking the first rate hike since 2018. Higher interest rates in the United States tend to exert downward pressure on all types of investments and can have worldwide ramifications.

The US dollar fell to 115.54 Japanese yen from 115.77 yen in currency trade. The euro fell from $1.1157 to $1.1145.