The rupee breached the 50 per dollar mark in noon trades, the level last seen on December 3, 2008. Earlier it opened at 49.71 against its previous close of 49.67/68 a dollar on Tuesday.
Traders attributed the plunge to banks buying dollars to arbitrage in the offshore non-deliverable forwards, which put pressure on spot rates. Yesterday, HSBC came out with a research report expecting INR to hit 54 levels against the USD.