Investors will scrutinise Powell's remarks for clues about the outlook for U.S. monetary policy, after a surprise hawkish shift from the Fed last week sent the dollar soaring and emerging market assets tumbling.

At 1550 GMT, the rand traded at 14.3525 against the dollar, 1% weaker than its previous close. It had gained more than 1% on Monday after steep losses of more than 4% last week.

Powell is due to appear before Congress from 1800 GMT. In prepared remarks he noted sustained labour market improvement and the recent increase in inflation.

Stocks ended largely flat with the broader Johannesburg All-Share index down a marginal 0.02% while the Top-40 index ticked just 0.04% higher.

"Given how markets remain highly sensitive to comments from Fed officials and inflation expectations, the next few days promise to be quite eventful for markets with numerous Fed speakers on the roster," Lukman Otunuga, Senior Research Analyst at FXTM said.

Chemicals and fertiliser maker Omnia Holdings was among the gainers, closing 1% firmer after it reinstated its dividend and posted a surge in annual earnings on Tuesday.

Mining stocks weakened 0.3% as gold retreated on a firmer dollar. [GOL/]

In fixed income, the yield on the benchmark 2030 instrument was flat at 9.065%.

(Reporting by Alexander Winning and Nqobile Dludla; Editing by Edmund Blair)