Stocks continued their slide, tracking a broad slump by emerging market equities on fears of a global trade war, which left the dollar struggling at 1-month lows. A slump by bourse heavy-hitter Naspers deepened the market's dip.
At 1415 GMT the rand was 0.72 percent firmer at 11.7725 per dollar, a touch softer than its session best of 11.7300, reached as trade in New York commenced with the cloud of escalating US China trade war sinking the greenback.
"There's sentiment in the market that Moody's won't downgrade us. This is reflected across fixed income and FX. There's no sense of deep anxiety, of uncertainty, about the rating review," said Halen Bothma of ETM Analytics.
The risk premium on the rand was also steady with implied volatility on one-week and one-month options down substantially from levels seen in November before new President Cyril Ramaphosa was elected head of the ruling African National Congress in mid-December.
"There hasn't been a big spike in implied volatility. Hedging activity hasn't picked up. The rand doesn't usually react like this when there's a big event like this where's there's a lot of money on the table," Bothma said.
Implied volatility measures how much an asset such as a currency is expected to move in price. When it falls, investors believe a currency will follow a more predictable trajectory.
Moody's is the last of the top three agencies to rank South African debt as investment grade.
A cut to junk would see Pretoria's bonds removed from Citi's influential World Government Bond Index (WGBI), triggering a selloff of up to 100 billion rand ($9 billion).
Bonds were also firmer, with the yield on the benchmark 2026 paper down 2 basis points to 7.99 percent, its lowest since Feb. 22.
On the stock market, the Top-40 index was down 1.48 percent TO 49, 791 points while the broader all-share fell 1.4 percent to 56,407 points.
Naspers was down 3.5 percent to 3,182 rand after announcing that it had sold two percent of its shares in Chinese Technology firm Tencent, reducing its holdings to 31.2 percent, to strengthen its finances.