About the Buy Back Bond Programme

Pls correct me if I'm wrong:
If the government buy back bond then the bond price will go up, that mean the yield will go down. If the yield go down then the investors will cash out from bond and invest into another things and it helps to stimulate the economy?
Pls show me
Thanks

Sounds good to me. Of course, we have to borrow money from China (or print it) to buy back the bonds. This contributes to the devaluation of the US Dollar and reduces consumer's purchasing power even further.