[edit] Market size and liquidity
The foreign exchange market is unique because of
its trading volumes,
the extreme liquidity of the market,
the large number of, and variety of, traders in the market,
its geographical dispersion,
its long trading hours: 24 hours a day (except on weekends),
the variety of factors that affect exchange rates.
the low margins of profit compared with other markets of fixed income (but profits can be high due to very large trading volumes)

According to the BIS,[1] average daily turnover in traditional foreign exchange markets is estimated at $3.21 trillion. Daily averages in April for different years, in billions of US dollars, are presented on the chart below:
This $3.21 trillion in global foreign exchange market "traditional" turnover was broken down as follows:
$1,005 billion in spot transactions
$362 billion in outright forwards
$1,714 billion in forex swaps
$129 billion estimated gaps in reporting