Unlike a stock market, where all participants have access to the same prices, the forex mall is divided into levels of access. At the culminating is the inter-bank market, which is made up of the largest investment banking firms. Within the inter-bank market, spreads, which are the difference between the bid and ask prices, are razor sharp and as usual unavailable, and not common to players outside the inner circle. As you descend the levels of access, the difference between the bid and ask prices widens (from 0-1 pip to 1-2 pips for some currencies such as the EUR). This is due to volume.
There will be a greater Forex Trading System demand, thus a tertiary school price, for currencies perceived as stronger over their relatively weaker counterparts. The Swiss franc back-number been a traditional safe haven during times of pressure group or material uncertainty.