You see, a lot of these large banks play this game where they "effectively" borrow money from the central bank at say 1% APR, and buy US Treasuries at say 2% APR. This is basically a way for the fed to give printed up money to the banks, and to finance the government for free. However, things like gold and silver which are a direct competitor to the US dollar for reserve status are a big threat to their profitability in these trades, so they willingly short the gold market, even if it means risking losses. Other countries around the world who know what's going on go along with this to stock up on their gold reserves at below market costs. Everybody wins, except for the people who want honest money, and who try to protect their savings by using gold.

If you blow up this short trade, then everybody is going to panic into gold. Also, the US central bank can only hope to bail out the losses of the banks by printing dollars, but that will drive the price of gold even higher. Then as the gold price rises, other countries will dump dollars and buy gold for reserves, driving the price even higher. Then, at some point the federal reserve will realize that they have to save the dollar, and you do that by ding, ding, ding, buying gold (and silver) on a massive scale to prop up the value of the currency and implicitly back it with precious metals.

We could literally wake up one morning to find every bank and government in the USA is bankrupt, and the price of gold is over 10000 per oz.