Johannesburg - The size of South Africa's current account deficit is likely to be the main driver of the rand on Tuesday, with data from the Reserve Bank forecast to show a gap of more than 6% Of GDP.
The rand was at R9.1220 to the dollar at 06:39 GMT, 0.3% weaker than its close in New York on Monday.
The Reserve Bank will release its quarterly bulletin at 08:00 GMT, including current account and spending data for the fourth quarter of 2012.
The data is expected to show a current account shortfall of 6.3% of GDP in the fourth quarter, compared with 6.4% in the third quarter, according to a Reuters poll on Monday.
A record trade deficit in January has already unnerved investors, as have wildcat strikes that have hit coal mines owned by diversified mining firm Exxaro Resources [JSE:EXX].
"The big number today is at 10 o'clock. That will be a game changer for the rand," said one trader.
"Deficits are the big problem. That's what's causing concern for foreigners. There have been a lot of foreign buyers of stocks and bonds, which traditionally is pretty hot money. It can exit any time."
Government bond yields edged higher, with the 2026 paper adding 1.5 basis points to yield 7.405% and the 2015 instrument up 1 basis point at 5.37%.