If i have a ganglion cyst on the backside of my wrist & iam moveing it for 8 hours 5 days a week why is it not growing in size it staing the same size?

It may not have a : Connection that stay open between it and the synovial or tenosynovial space that it evolved from. While at times motion may "pump" up the ganglion ( like the bladder in a reebok sneaker or skate) many times the one way valve from teh adjacent joint tendoin or essentially a synovial cavity to ganglion may be closed . The ganglion is filled with synovial fluid that can't escape back to where it came.

Varys: Ganglion cysts can behave in a number of ways. They can grow, stay the same, or even shrink. They can cause pain or be asymptomatic. I would say you are lucky.