In August 2011, gold was at $1,900 with 20MA volume of 2,200,000. If you divide the volume by the price, you get a number, 1160. 1160 can serve as the sentiment factor.
In Dec 2020, people will have ample time to determine that the dollar is crashing and that the only safe-haven is gold. The 20MA volume in Dec 2020 will be about 20,000,000. Divided by 1160, (the sentiment number for max bull market gold shown earlier), you have a price of $17,200.