Greece's stock market reopens after a month, plunges over 22 percent in early trading

A man walks with his dog past a mural at a central neighborhood in Athens, Greece, on Sunday, Aug. 2, 2015. In Athens, the heads of the EU-IMF audit mission met with the Greek ministers of finance and economy with the talks focusing on bank recapitalisation, privatisations and fiscal targets, the finance ministry said. (AP Photo/Yorgos Karahalis) (The Associated Press)

A man carries a closet past an abandoned branch of the National bank in Athens, Greece, on Sunday, Aug. 2, 2015. In Athens, the heads of the EU-IMF audit mission met with the Greek ministers of finance and economy with the talks focusing on bank recapitalisation, privatisations and fiscal targets, the finance ministry said. (AP Photo/Yorgos Karahalis) (The Associated Press)

Shares on the Athens Stock Exchange are suffering huge losses of over 22 percent after the market reopened for the first time in more than a month.

The main index plunged early Monday after the country's Capital Market Commission formally approved the reopening of the exchange.

The exchange and Greek banks were closed on June 29, when controls on money withdrawals and transfers were imposed to prevent a collapse in the banking system due to a run on deposits.

Banks have since reopened, while maintaining strict withdrawal limits.

Greece is currently locked in intense negotiations with bailout lenders in an effort to negotiate the terms of a massive new rescue package in the next two weeks.