President Joe Biden's midday announcement that a bipartisan group of Senators had reached a deal to pass an infrastructure bill had little effect on the bond market.
Business reopenings from COVID-19-related shutdowns have accelerated this month, and investors are also pricing for higher inflation as fiscal spending increases.
"With the reopening process, it seems to have hit a higher gear in April," said Tom Simons, a money market economist at Jefferies in New York.
Rand was 0.54% weaker at 15.4350 per dollar, having earlier plunged to a session-low 15.5700, its weakest since Jan. 12 in a fourth straight day of losses.
"We continue to believe that the domestic currency will average weaker in Q2.21, around R15.40/USD, with high risks to the downside."
Ten-year gilt yields rose to 0.835%, 4 basis points up on the day, after Bank of England Chief Economist Andy Haldane warned that an inflationary "tiger" might be on the loose which could require more BoE action than markets expect.
Five-year gilt yields also rose to their highest since March 2020 at 0.413% and their spread over German five-year bonds widened above 93 basis points , also the widest since March 2020.
The $1.9 trillion stimulus package looks likely to be approved by Congress, bypassing Republican roadblocks.
Ten-year borrowing costs extended their rise to the highest since last March at 1.2%, while 30-year yields touched 2% for the first time since mid-February 2020 .