The floating exchange rate between the Philippine peso and the U.S. dollar means that it changes constantly because currency trading never stops, according to Investopedia. Each time that someone either trades for or trades away one of the currencies, its value either rises or falls relative to the other.
The Philippine peso has been permitted to float since 1964, as stated by Investopedia, though there were rules that limited the extent of exchange rate changes, as explained by International Economics. These have been abolished. For example, 1998 saw the abolishing of the volatility banking system, which would suspend trading if the exchange rate changed by more than 6 percent of the previous day's exchange rate.