How useful is volume to a forex trader?

Volume is a just a way of looking at charts in unnecessarily sophisticated way.

What do you mean by unnecessary? that's a very big statement to make, without going in dept.

-Main concept: It basically comes down to understand what (kind) of information really matters.

-Unnecessary: One doesn't really need to put volume indicator to tell what the (relative) volume is, but exact volume is of little importance. There are concepts like ''weakness'' ''hidden potential selling'' and then "volume gurus" would point at volume indicator showing some extreme reading. I find it funny, because the same thing can be seen just by looking at candlesticks/bars. Volume analysis (just like many other analysis and indicators) translate to similar concepts in different types of analysis.
Why should one look at volume if: the same can be seen from candlesticks; more people (and algoritms) make their judgements based on candlesticks?

-Another comparision: That is somewhat similar to looking at line charts in addition to candlestick charts.

It's true that one doesn't need to care about volume, which is different than needing it, but I get what you are saying. But for knowing the market at a quick glance there is nothing like it. For example I shorted 3 stocks today, one of them is yahoo, this is a short term short but I will ride it out as long as I could. And another 2 stocks for 2 companies I have never heard of in my life, i don't even know a thing about them, I just went to the biggest stock gainers and losers and picked out the stocks I think are the best for a short, seeing as the stock market falls faster than rise I favor shorting for short term and going long for longer periods of time.

But without volume I wouldn't be able to pick out those stocks so quick, another example is the NZD dollar which has been weak for a few days, and plugged today I am still in it, and riding it out. Another example is the inflation that happened on gold, gold went up on low volume and was like a leaf in the wind just sitting to be knocked over, and it got just that and left man speculators scratching their heads, I don't trade gold yet so didn't matter to me much. In forex volume is more important that many realize, although I don't use it in the form of tick volume for my trading, but if you want to get technical, it can show where the walls are, I am not going to get into that.

But if you are doing good trading FX without it then that's good. But for me right now, where I am trying to go in many different markets, to diversify volume is the only way that I can see manipulation. Price action can tell you some of it, but not all, as the market can go either direction on weak volume, and you never want to trade with weak volume, unless you know the danger. Anyway may the pip be with you.