my speedometer spindle is not moving, what is the cause
Hmmm....it's broken?
Honestly, no way to be sure without seeing the car and diagnosing the problem, as there could be several different causes, or a combination thereof.
Could you provide everyone a bit more to go on, such as the total mileage on the vehicle, when this problem first occurred, if there were any other associated incidents, (such as an accident/crash), the year/make/model of the vehicle, what if any diagnostic attempts have been already made, is the speedometer making any noises, is the odometer functioning, but the speedometer is not, etc.