The ruble rallied, reversing an earlier slide, as speculation mounts that Russia’s central bank will take steps to stem the worst weekly rout since 2009 as tension mounts in Ukraine’s east.

Russia’s ruble climbed 2.3 percent to 45.8000 per dollar at 3:01 p.m. in Moscow, after falling as much as 3.7 percent earlier. The currency retreated 6 percent this week, the most since February 2009 on a closing basis. The yield on 10-year government bonds fell one basis point to 10.08 percent.

Traders have this week been trying to gauge how far the ruble will fall before the Bank of Russia steps in with a large intervention to shore it up after Russia moved closer to adopting a free-floating exchange rate. Escalating fighting in Ukraine and Brent crude’s longest stretch of weekly losses since November 2001 are pressuring the ruble. Speculation that the central bank is holding an emergency meeting are driving today’s gains, according to Citigroup Inc.

“The turnaround must be related to speculations about possible CBR actions,” Ivan Tchakarov, the chief economist at Citigroup in Moscow, said by e-mail. “The market is very jittery now and it responds to any rumors, speculations etc. I dont think what we have been seeing the last couple of days can in any way be linked to market fundamentals.”

The Bank of Russia abolished its predictable intervention policy on Nov. 5, while including a caveat reserving the right to sell foreign currency unannounced if it deems there’s a threat to the nation’s financial stability.

Ukraine Tension

The ruble’s 28 percent drop since the start of the year is the biggest among 31 major currencies tracked by Bloomberg. The selloff was exacerbated in the past month by oil’s slide to four-year lows in London, which curtails revenue for the world’s largest energy exporter.

The crisis in Ukraine is coming to a head after Ukraine and its allies accused separatists of undermining peace efforts with Nov. 2 elections in Donetsk and Luhansk. Russian President Vladimir Putin said Nov. 5 that Ukraine’s “civil war” isn’t subsiding as cities continue to come under shelling and the civilian death toll rises.

The yield on Ukrainian bonds due in July 2017 climbed 12 basis points to 15.81 percent, bringing this week’s increase to 2.42 percentage points, the most since January.

Under the new exchange-rate rules, the central bank spends $350 million just once a day to support the ruble when it falls past its lower trading band. Previously, it would pour in $350 million each time the ruble fell by 5 kopeks past the boundary before moving the band again and repeating the process, enabling traders to profit from keeping short currency positions.

“Today’s movements are likely due to the excessive weakening of the previous few days,” Vladimir Evstifeev, an analyst analyst at Bank Zenit in Moscow, said in an e-mailed note. “Market participants who fear more decisive and unorthodox steps by the central bank are taking profits.”