Russia’s stock index reopens and rises with government intervention.

After shutting down for almost a month, the Russian stock market reopened for limited trading on Thursday. Just 33 companies, all listed in the benchmark MOEX index, were allowed to trade on the Moscow Exchange for four hours and ten minutes.

The MOEX index rose 4.4 percent, but it was probably buoyed by significant government policies intended to avoid a sell-off, including a measure to bar foreigners from selling stocks.

The Russian central bank said on Wednesday there would be a ban on short selling the stocks, a type of trade involving a bet that a company’s share price will fall. Previously, the government had said it would instruct its sovereign wealth fund to channel up to $10 billion into local stocks to stop their prices from plummeting. And in late February, the central bank barred brokers from executing sell orders by foreigners.

The White House called the partial reopening a “a Potemkin market opening.”

It was the first opportunity for local stock trading since Feb. 25. The day before trading was halted, the index dropped to a record low after Russia invaded Ukraine. It then partially rebounded.

On Thursday, the index rose as much as 11.8 percent shortly after trading began, but then lost most of that gain. Just 33 of the 50 stocks in the benchmark index were tradable.

“This is not a real market and not a sustainable model — which only underscores Russia’s isolation from the global financial system,” Daleep Singh, the U.S. deputy national security adviser for international economics, said in a statement on Thursday. “The United States and our allies and partners will continue taking action to further isolate Russia from the international economic order as long it continues its brutal war against Ukraine.”

On the Russian exchange, shares in oil and gas companies rose, including Gazprom, which gained 13 percent; Rosneft, which rose about 17 percent; and Novatek, which rose 19 percent. The mining companies EN+ Group and Norilsk Nickel also climbed by about 3 percent and 10 percent respectively. Shares in VTB, a bank that has recently come under sanctions, fell nearly 6 percent. Shares in Aeroflot, the Russian airline, dropped 16 percent.

Overseas, Russian stocks have been ejected from indexes after losing most of their value.