Peter Attard Montalto, emerging markets economist at Nomura International, on Monday moved to provide additional colour to explain the rand's earlier spike.

"Tokyo Financial Exchange (TFX) has currency futures, where investors are able to trade FX on margin. Last Friday, TFX announced that the closing price of the rand/Japanese yen was 8.4150, thus the long rand/Japanese yen position in the exchange would be triggered on the market open on Monday," Attard Montalto said.

He said that TFX currently fed prices from five banks, and it appeared that one of them showed a very wide bid/offer (3 Yen wide) price at the close of Friday, with somebody hitting a very wide bid at 8.4150.

"Since it is a good print on the exchange, the stop loss orders and margin calls were all triggered this morning at the market open today, thus we saw US dollar/rand spiking up to 8.2550 (some say 8.5000 high) and US dollar/Japanese yen dropped down to the low of 89.18 at the same time," Attard Montalto said.

"At the end of close on Friday, there were about 3600mio rand/Japanese yen long on TFX and looks like 2300mio rand of them were forced out this morning.

"It looks like nobody can reverse this despite the off market hit of 8.4150 because it is a good print on the TFX on Friday," the economist said.