Large hedge funds and other well capitalized "position traders" are the main professional speculators.
Currency speculation is considered a highly suspect activity in many countries. While investment in traditional financial instruments like bonds or stocks often is considered to contribute positively to economic growth by providing capital, currency speculation does not; according to this view, it is simply gambling that often interferes with economic policy. For example, in 1992, currency speculation forced the Central Bank of Sweden to raise interest rates for a few days to 500% per annum, and later to devalue the krona. Former Malaysian Prime Minister Mahathir Mohamad is one well known proponent of this view. He blamed the devaluation of the Malaysian ringgit in 1997 on George Soros and other speculators.
Gregory Millman reports on an opposing view, comparing speculators to "vigilantes" who simply help "enforce" international agreements and anticipate the effects of basic economic "laws" in order to profit.
In this view, countries may develop unsustainable financial bubbles or otherwise mishandle their national economies, and forex speculators allegedly made the inevitable collapse happen sooner. A relatively quick collapse might even be preferable to continued economic mishandling. Mahathir Mohamad and other critics of speculation are viewed as trying to deflect the blame from themselves for having caused the unsustainable economic conditions. Given that Malaysia recovered quickly after imposing currency controls directly against IMF advice, this view is open to doubt.