But soon the funds grew huge and were in fact able to move the exchange rates through their interventions. The famous herd instincts replaced economic fundamentals. With the invention of arbitrage and futures trading, the need for exchange-rate stability for the purpose of trading gave way to the desire of currency traders to make massive amounts of money in the shortest possible time. An artificial system of devaluation and revaluation of currencies was devised which enabled currencies to be appreciated or depreciated literally within seconds. Thus the Indonesian rupiah was at one time devalued by more than 600 per cent, then in the space of a few days recovered by 200 per cent. It is still moving up and down by 100 per cent to 200 per cent in the space of one day or even half a day.