(Reuters) -The Russian rouble tumbled to a record low in extremely volatile trade on Monday, losing a third of its value so far this year, but an emergency rate hike and other urgent measures adopted by the central bank helped it trim losses. The Bank of Russia had sold around $1 billion from its reserves on Thursday, Feb. 24, the day Russia invaded Ukraine. But Governor Elvira Nabiullina said the central bank had stopped interventions on Monday due to the latest western sanctions, suggesting the rouble was supported by other unnamed market participants. On Monday, the finance ministry and the…