I'm curious to know what sort of timeframes they were manipulating on. Most if the large institutional banks are operating as market makers, which would likely limit their influence on price movements to a few pips at most. Most institutional investment firms in forex are not trading as market makers though...typically operating on much larger time horizons...hours to days. The amount of capital necessary to manipulate the currency on those timeframes is incomprehensible. I doubt even the 16 largest banks in the world, even working as a deal facto cartel, could coordinate price manipulations bigger than 50 pips over the course of a day. I mean we're talking about a quarter of the GDP of the entire US changing hands every single day via these markets. These banks are massive, but still nowhere near big enough to materially affect the markets. It makes me wonder what sort of damages are being claimed, and how they are calculating those damages.