Gold vs. DOW; Looking to History for Help

Was reading about China crashing stock market and got looking into the drop during Great Depression. Then was looking at entire history of DOW value. Then came across this interesting chart which compares DOW value to Gold value. Since gold has a real value vs. fake money it's interesting to see the correlation between the two. Only two conclusions to be made from this: stock market is over valued or gold is undervalued. The way things are going I would be willing to bet that the stock market is over valued and due for a drop, big drop. At the same time gold is a bit anemic and could stand to rebound to 1300-1500 range. Thoughts?