Distribution occurs prior to a downtrend. Distribution is the process of "smart money" selling shares without significantly affecting price. Source: school.stockcharts.com/doku.php?id=glossary_d
The attributes of distribution:
1) It occurs after an advance. 2) Price should form some sort of a topping pattern. E.g. a double top, rising wedge, etc. 3) Price should not be making new highs.
I think that a lot of the USD pairs are distibuting.