In this article, we have tested the full information maximum likelihood, (FIML) of the natural logarithmic monthly returns of the CAD/USD, DKK/USD, CHF/USD and JPY/USD spot exchange rates. We have applied a system of four equations of the spot exchange rates to test and spot volatility clusters. The coefficient C(1) of the CAD/USD spot exchange rate is not significant at the 5% significant level. The coefficient is 0.000937, the z-statistic is -0.646 and the p-value is 0.5183. The standard error is 0.001450. The log likelihood is 507.9283. The average log likelihood is 2.49. The Akaike, Schwarz and Hannan-Quinn criterion are - 4.97, -4.95 and -4.96 respectively. The coefficient C(2) of the DKK/USD spot exchange rate is not significant at the 5% significant level. The coefficient is - 0.001560, the z-statistic is -0.946 and the p-value is 0.3441. The standard error is 0.001648. The log likelihood is 476.7551. The average log likelihood is 2.34. The Akaike, Schwarz and Hannan-Quinn criterion are -4.66, -4.65 and -4.66 respectively. The coefficient C(3) of the CHF/USD spot exchange rate is not significant at the 5% significant level. The coefficient is -0.003, the z-statistic is -1.73 and the probability is 0.0836. The standard error is 0.001708. The log likelihood is 470.50. The average log likelihood is 2.30. The Akaike, Schwarz and Hannan-Quinn criterion are -4.60, -4.59 and -4.60 respectively. The coefficient C(4) of the JPY/USD spot exchange rate is not significant at the 5% significant level. The coefficient is 0.00018, the z-statistic is 0.107 and the probability is 0.9146. The standard error is 0.001654. The log likelihood is 475.0964. The average log likelihood is 2.33. The Akaike, Schwarz and Hannan-Quinn criterion are -4.65, -4.63 and -4.64 respectively. The best fit model that helps the arbitrageurs to craft their investment strategy in terms of buying or holding large portfolios of spot exchange rates is the CAD/USD represented by equation 1. It has the largest value of the log likelihood and average log likelihood value. The values are 507.9283 and 2.49 respectively. In addition, the CAD/USD spot exchange rate has the lowest error term value of the Akaike, Schwarz and Hannan - Quinn information criterion. The numerical values are -4.97, -4.95 and - 4.96 respectively. Moreover, the CAD/USD spot exchange rate has the lowest standard error, which equals to 0.001450. The data that we have used started from 01/10/2000 to 01/09/2017 and represent the CAD/USD, DKK/USD, CHF/USD and JPY/USD spot exchange rates, which total to 204 observations. The data was obtained from the Federal Reserve statistical release department and it is denoted by the symbol, H.10.