This happens when there is lag in the server. Has nothing to do with people using any kind of cheat engine or speed clicking rewards. The server falls out of link all the time. It can be really irritating when it shows you have 100 gem stakes but when you hover it's really only experience. I have also see it show that i have 4 bill credits instead of 400k every now and then. It works like most equipment, just need to refresh and reset to see your proper values of everything.