MT4 Info

There is Tick, PIP, and Point. They are all different in general. A tick is the smallest change of price. A Point is the least significant digit quoted. In currencies a pip is defined as 0.0001 (or for JPY 0.01)

On a 4 digit broker a point (0.0001) = pip (0.0001). [JPY 0.01 == 0.01] On a 5 digit broker a point (0.00001) = 1/10 pip (0.00010/10). Just because you quote an extra digit doesn't change the value of a pip. (0.0001 == 0.00010) EA's must adjust pips to points (for mq4.) In currencies a tick is a point. Price can change by least significant digit (1.23456 -> 1.23457)

In metals a Tick is still the smallest change but is larger than a point. If price can change from 123.25 to 123.50, you have a TickSize of 0.25 and a point of 0.01. Pip has no meaning.

This is why you don't use TickValue by itself. Only as a ratio with TickSize. See DeltaValuePerLot()