The rand continued its firm run in midday trade on Thursday amid aggressive selling of US dollars and rand buying in London "to take out the stops," a local trader said.
At 11.47am the rand was bid at R7.25 to the dollar, R9.79 to the euro and R11.01 to the pound. The euro was bid at $1.3500 from $1.3506 previously.
The trader said: "There are no external drivers to explain the rand's strength. We have seen aggressive selling of US dollars, and rand buying in London, with bullish moves to take out stops."
Dow Jones Newswires reports concern that US non-farm payrolls Friday may prove disappointing and book squaring ahead of the long Easter holiday weekend in most of Europe left the dollar and the euro narrowly mixed in European trading Thursday.
With concern over Greece's debt problems still looming large, the euro failed to take much comfort from data showing that the euro zone's purchasing managers' index for manufacturers rose to a 40-month high.
Disappointing payroll figures will lower expectations of an early hike in US interest rates and could undermine recent support for the dollar.
Nevertheless, the market's response to all this could be subdued given that both Friday and Monday are holidays in most European trading centres and turnover in currency trading has already declined as market participants square their books and move out of the market.