Before revision:  Cross et al. (2012) , where was shown that for the case of four currencies arbitrage chains may be periodic or exponentially unstable. In contrast with the four-currency case, we find that arbitrage operations when d >= 5 currencies are present may appear very unstable, with the exchange rates growing in accordance with the double exponential law !
After revision:  Cross et al. (2012) , where was shown that sequences of triangular arbitrage operations in FX markets containing 4 currencies and trader-arbitrageurs tend to display periodicity or grow exponentially rather than being self-extinguishing. This paper extends the analysis to 5 currencies are present may appear very unstable, with the exchange rates growing in accordance with the double exponential law !