InformedTrades

As global stock markets have plummeted in the last few days, both Greece and South Korea have banned the short-selling of securities, the attempt by some investors to make money by betting that their holdings will decrease in value. On Monday, Greece ordered a halt in the short selling of stocks, and South Korea did the same on Tuesday. In both countries, stock indexes fell sharply in the aftermath of Standard & Poor's downgrading of the U.S. government's credit rating, and cost investors billions of dollars in losses.

The trouble initially flared on Saturday night following a peaceful protest in Tottenham over the fatal shooting of Mark Duggan by police. But by Tuesday morning a large number of London boroughs had been left devastated by the trouble, with violence also erupting in cities away from the capital. Here is a breakdown of the locations of last night's violence. You can see the locations on our interactive map here.

Swiss stocks slid for a 12th day, extending the Swiss Market Index (SMI)'s longest losing streak on record, as banks retreated amid concern the global economy is faltering. Credit Suisse Group AG (CSGN), Switzerland's second-largest bank, plunged to its lowest price since 2003.

Standard & Poor's has begun to downgrade states and municipalities Monday morning after stripping the federal government of its 'AAA' rating. While not unexpected, the move has far-reaching implications for thousands of local governments already burdened by steep deficits.

After S&P caused a mayhem in global markets by lowering its credit rating for the US, rival rating agency Moody's today said it was convinced about its 'AAA' rating and would consider a downgrade only if the United States fails in efforts to reduce its fiscal deficit. Moody's said it was keeping its top-notch 'AAA' rating intact for the US, as it was hopeful of further improvement in the economy and additional measures for lowering of budget deficit by 2013.

The New York Stock Exchange early Monday put into effect its so-called "Rule 48," aiming to smooth the opening of U.S. stock trading in what is expected to be a rocky session. Rule 48 allows designated market makers on the NYSE to refrain from disseminating price indications ahead of the opening bell. The idea is to make it easier and faster to open stocks on days when trading is poised to become especially volatile.

"People are very concerned that rice supplies may be smaller on fear of radiation contamination," Nobuyuki Chino, chairman of the exchange's rice futures trading committee, told reporters in Tokyo. "This was reflected in the prices," said Chino, who is also president of Tokyo-based grain company Continental Rice Corp.

Copper futures fell in New York, capping the biggest weekly slump since June 2010, on concern that the faltering global economy will curb demand for industrial metals. Copper declined for the fifth straight day as a report showing U.S. employers in July added more jobs than forecast failed to ease concern that the nation will slip into another recession. All six base metals traded on the London Metal Exchange dropped, with lead and zinc falling more than 5 percent and tin had the biggest weekly drop in two years.

The head of Standard & Poor's sovereign ratings said Sunday that the agency may downgrade the U.S. again. "Given the economic and political situation in the U.S., which will we see, an upgrading back to AAA or further downgrades?" Fox News' Chris Wallace asked David Beers. "We have a negative outlook on the rating and that means we think that the risk currently for the rating are to the downside," Beers said.

China sold Japan's medium- and long- term debt for the first time in nine months in June as the yen traded near a record high against the dollar and benchmark yields approached their lowest level since November.

The People's Bank of China set its daily fixing 0.23 percent stronger at a record 6.4305 per dollar, the biggest advance since November 2010. The currency is allowed to trade up to 0.5 percent on either side of the official rate.

The Group of Seven nations is committed to taking coordinated action to ensure liquidity and to support financial market functioning, financial stability and economic growth, G7 finance ministers and central bank governors said in a statement.

Timothy Geithner informed President Barack Obama that he will stay as Treasury Secretary at least through the 2012 election.

We have lowered our long-term sovereign credit rating on the United States of America to 'AA+' from 'AAA' and affirmed the 'A-1+' short-term rating. We have also removed both the short- and long-term ratings from CreditWatch negative.

Energy released from solar plasma blasts will reach Earth throughout Friday and Saturday, potentially disrupting communications and electrical grids, according to the National Oceanic and Atmospheric Administration. The explosion on the sun's surface could affect precision satellite systems such as GPS and high-frequency radio waves, which airlines use for communication.

There was crazy chatter about this earlier, and now CNBC is reporting that the government is preparing for a possible downgrade from S&P. Remember, during the debt ceiling fight, S&P warned that there was a 50/50 chance of a downgrade if spending weren't cut by at least $4 trillion dollars.

The Australian dollar headed for its biggest weekly decline versus the greenback since May 2010 after the Reserve Bank cut its forecast for 2011 economic growth.

South Korea should raise its benchmark interest rate to at least 4 percent over time and allow its currency to appreciate further to better fight inflation, the International Monetary Fund's staff said.

The franc weakened after Swiss National Bank President Philipp Hildebrand called the currency's strength "absurd" and said the bank won't exclude "further measures" to curb its advance.

Option prices in Europe rose for an eighth day and the benchmark index for contracts in Hong Kong surged the most ever as concern intensified that global economic growth is slowing faster than expected.