MOSCOW (Reuters) – The rouble strengthened on Friday, heading towards the 71 mark against the dollar as a highly volatile year drew to a close, with the final month of trading dominated by fears over the impact of a Western oil price cap on Russia’s export revenues.

At 0708 GMT, the rouble was 1.3% stronger against the dollar at 71.22, recovering some ground from the eight-month low of 72.9175 hit in the previous session.

The rouble has lost around 13% to the dollar since the price cap on Russian oil exports came into force on Dec. 5, although analysts have said the technical impact would be more strongly felt in January-February.

It had gained 0.6% to trade at 75.54 versus the euro and firmed 1.7% against the yuan to 10.01.

The finance ministry on Friday said the maximum possible share of Chinese yuan in its National Wealth Fund (NWF) had been doubled to 60% as it restructures its rainy-day fund to reduce dependency on currencies from so-called “unfriendly” nations.

Recovering imports, which collapsed in the wake of Russia sending tens of thousands of troops into Ukraine as the West imposed sanctions and companies left the market, have also contributed to the rouble’s weakening.

“Even in a pessimistic scenario, the current account surplus could remain at a historically high level, providing the rouble some support,” said Dmitry Polevoy, head of investment at Locko Invest.

“Our estimates vary from 67.4 to 81.1 per dollar on average in 2023.”

Brent crude oil, a global benchmark for Russia’s main export, was up 0.6% at $84.0 a barrel.

President Vladimir Putin this week delivered Russia’s long-awaited response to the price cap, signing a decree that bans the supply of crude oil and oil products from Feb. 1 for five months to nations that abide by it.

Russian stock indexes were higher.

The dollar-denominated RTS index was up 1.6% to 951.8 points. The rouble-based MOEX Russian index was 0.2% higher at 2,151.1 points.

(This story has been refiled to fix the spelling of ‘rouble’ in the headline)

(Reporting by Alexander Marrow; Editing by Alex Richardson)