BUENOS AIRES, Argentina - The stock market in Argentina crashed on Monday, losing more than third-of-its value. while the Argentine peso dived causing the central banbk to intervene.

The key index on the Argentine Stock Exchange, the Merval, collapsed after a primary election saw a significant swing to the opposition, seen as a challengine to the government of Argentine President Mauricio Macri.

Macri is facing stiff opposition from opposition candidate Alberto Fernandez and his running mate, former president Cristina Fernandez.

The MERVAL index fell a massive 16,824.29 points, or 37.93%, to close at 16,824.29.

The peso dived by 30%, but had managed to trim the day's losses to 15% by the end of the day, which was marked by extreme volatility.

The crash in the stock and currency markets, which spread to the bond market is putting Argentina's financial system under threat, for the first time since the country defaulted on its current debt causing a financial crisis, in 2001.

Despite the primary election result, which put the Fernandez team 15.5% ahead, remains optimistic of retaining government.

"I trust we will have a more even election in October that will allow us to go to a second round," he said Monday. "Those who don't want to go back to the past will join us."

Bond yields soared and prices fell by 18 to 20%, leaving 10-year bonds, and century-bonds, trading at 60 cents on the dollar.

The Argentine central bank is believed to have sold more than $100 million of foreign exchange reserves to support the peso.

The falls in Argentina impacted on Wall Street, sending stocks with interests in the country reeling.

The Dow Jones Industrial Average plummeted 391 points, or 1.49%, to 25,896.44.

The Standard and Poor's 500 shed 35.96 points, or 1.23%, to 2,882.69.

The Nasdaq Composite declined 95.73 points, or 1.2%, to 7,863.41.

The safe-haven currency, the Swiss franc, rose sharply to 0.9690. The Japanese yen, also favoured in times of uncertainty, was well bid at 105.27.

The euro rose from the ashes in Asia where it had dropped under 1.1200 to 1.1165. By the close in New York Monday, the European Union currency was fetching 1.1215.

The British pound fell to 1.2077, but that was an improvement on its close in Asia at 1.2059.

(Photo credit: iStock).