How can tick and volume charts work for FX?

Hi, I have a simple question, maybe:

I read on the web about tick or volume charts being used for forextrading - but it doesnt make any sense to me, since the forex market is an OTC market, which means: no one knows - minute by minute - how many trades go through. And if a tick chart is made up of the trades that are being executed in a market - then how can they make any sense at all? If they are based on your brokers volme - then it would seem ridiculous to me - any broker is only a fraction of the market (except Deutsche Bank, of course).. So - does DB offer tick charts?

Which chart types are the best for forextraders, then?
Range charts?
Renko charts?
Time charts?
Others?

Hi, there must be someone who has an input/opinion on this?

not sure if every broker but the tick chart on mine correlates with quote movement. and It is extremely useful.

zoom out and add some reference points and you can trade off of it.

at least in my view all chart say the same thing, its just a matter of knowing what to look for

I've found Tick Volume useful for trading on the one-minute chart & M15, less on others.

Maybe in futs but not in spot, like you say it's OTC!

A large percentage of retail trades don't go anywhere near the market anyway, they're dealt with in-house, besides which quotes are only loosely based on the underlying market, marketmakers book, and liquidity providers quotes.