Subsequently it has fallen back again and was trading between 85 cents to 90 cents at the beginning of October. Although it did have this immediate impact, it is doubtful if this one-off intervention will have the desired effect over a longer time period.
Intervention normally only works if it is aimed at stopping speculative capital flows, if it signals a change in underlying policies, if it is strongly supported by all parties participating and if the central banks are prepared to intervene repeatedly and in large amounts. These are also the main reasons that the South African Reserve Bank did not intervene in the foreign exchange market.