Often yes but sometimes they both go down. However bonds don't decline as fast. The actual strategy I follow is stock/bond/short-term. The short term is like a buffer currently invested in short term treasury fund. Think of it like a game. If stocks are low then sell bonds and when that is also low then use the short term investment to live on to wait out the market recovery. Also if you are retired like me you would tighten expenses when drawing from the short term during a downturn.