Brazil's Sao Paulo Stock Exchange tumbled 14.78 percent on Thursday, its worst one-day fall in 21 years, as investors were upset about the economic impact of the novel coronavirus.

The Brazilian real also took a hit, sliding 1.38 percent against the U.S. dollar to a new record low of 4.78 reals.

The stock exchanges suspended trading twice as steep drops in value triggered the so-called circuit breaker to temporarily halt operations.

The mechanism automatically activates when the market loses more than 10 percent of its value, giving investors time to reconsider.

Many analysts said the performance of the market on Thursday was partly impacted by the U.S. decision to ban flights from many European countries to curb the spread of the virus.

To shore up the real, the Central Bank of Brazil injected 2.5 billion dollars into the market after the local currency opened trading at 5.01 to the dollar. It closed the day at 4.78 reals to the dollar.

"This scenario will last several weeks and will definitely affect the entire first half of the year," said Joelson Sampaio, an economic expert at the Getulio Vargas Foundation in Sao Paulo.

"Investors believe Brazil's companies will be affected by the coronavirus, and the most affected areas are the airlines and the oil company Petrobras," he added.

Brazil's state-controlled oil and gas giant Petrobras' stocks slumped 21 percent, and leading airline Gol's stocks plummeted 29 percent.