"The Singaporean dollar tumbled to a 4-year low against the US dollar after the Monetary Authority unexpectedly stymied currency appreciation. The move is just the latest in the trend of weaker currencies in 2015.
Singapore, a compact financial center, uses exchange rates instead of lending rates to control its currency, as it is a very trade-oriented economy.
The bank also reduced its inflation target, forecasting a negative 0.5 percent in consumer prices for 2015."