"Why basically forex trading volume is not considered in technical analysis?"

[sarahfx]

International foreign exchange market is an open and invisible market. Advanced communication tools make the global foreign exchange forex markets into one.
The market participants could do forex trading all around the world without limited of time and space.
So it is a very hard work to calculate the foreign exchange transactions within a period.
So in the foreign exchange market, technical analysis is done without considering the volume of foreign exchange.
This is also one of the differences between technical analysis of forex trading and stock trading.