Russia’s stock market is set to have a partial reopening Thursday, nearly a month after it shut down following the invasion of Ukraine

The challenge for Moscow is that the resumption of trading could simply send Russian stocks back into free fall. On Feb. 24, the day when President Vladimir Putin began the assault on Ukraine, the main Russian stock index tumbled 33%. While the index regained a fraction of those losses on Feb. 25—its last day of trading—that was before Western sanctions hammered the ruble and sent the country into an economic crisis.