Volume data and analysis is commonplace in the equity market several popular technical indicators depend on the easy availability of volume but in the spot forex market, volume numbers are a proprietary secret of the banks and brokers executing the trades.

The business is, literally, private. When a fund or multinational corporation has a big trade to do, such as $2 billion in a day (or over two or three days), they tell their banks not to move the market as they execute the orders. So, even when you see a big price move, you never know whether it had real money behind it, meaning it was an authentic commercial transaction such as a foreign acquisition or a new stock or bond position, or if it was a speculative move by a hedge fund.