m3rlin

China is one of the largest gold producers on the planet and all gold mined in China, stays in China. A lot of those that study these markets Alasdair Macleod and others all suggest that China has a lot more gold than published via the World Gold Council. 
Even if they only mine 300 tonnes annually in China, multiply that by 20 years, that's 6,000 tonnes, plus all they've bought over the last several years on the OTC markets etc..  

I'd hazard a guess that they have 8,000 tonnes or more. 

China have been selling US T-bonds and buying gold, they've reduced their Treasury holdings massively over the last few years. All that currency has to go somewhere, it's not all gone into propping up their own markets. That would then have spiked inflation by flooding their own markets with liquidity. 

If Biden can issue $4 trillion+ in spending plans and the USA can be $35 trillion in debt, then the Treasury can have $600 billion in gold, it's basically a rounding error. There are black budget agencies with bigger budgets than that. Put yourself in the position of a global puppet master able to print your own money with zero oversight. Would you leave yourself poor or would you own a monster stack of gold and every other asset on the planet? 
China is a poor country. The GDP per capita is $12,500 (IMF, 2023) and the lion's share of that is concentrated on the East Coast, where the GDP per capita is similar to Japan or South Korea ($30-35K). The west of China is one of the poorest regions anywhere on earth. China has only been an economic powerhouse for about 30-40 years. The European dynasties were powerhouses for centuries.
The USA essentially took most of the gold from the two most powerful Empires - Britain and France (also Germany) - during WWI & WWII. That's why the USA was given global reserve currency status at Bretton Woods - they took most of our gold and their manufacturing base existed in splendid isolation from war damages while Europe, China and Japan were reduced to rubble. Both Britain (Canada) and France (USA) transferred the majority of their gold, several thousand tons, to North America circa 1940 before the fall of France.
Under the USA's terms of neutrality, which lasted until after December 1941 (Pearl Harbor) no credit could be used to fund the war efforts of the UK or France - gold and USD (convertible to gold) were the only acceptable forms of payment. Thus all the gold the French and British transferred to North America ended up in the pockets of the Americans, along with the USD reserves. By the conclusion of WWI and WWII the USA had control over global finance and held a substantial chunk of the hard currency accrued by the Europeans over centuries, including the gold the Europeans took from China and India
China is on a desperate gold buying spree not because China has the biggest stack in the world but because their stack is basically non-existent relative to the size of their population - about 1g per capita compared with India's approx 17g per capita.
China needs the gold to hedge against their property market (the largest physical market in the world), their manufacturing sector and currency risk, while also signalling to the world that no matter what happens, China has the means to stabilise its economy. When the size of China's property market is roughly $50 trillion compared to the USA's $30ish trillion, China has a lot more gold to buy before it can effectively hedge anything. 

Hello! 
For sale: 8 x 1/20oz Gold Coins, mixed date maples and nuggets plus 2004 Monkey from the Lunar series.
£800 for all 8 posted Special Delivery.
Any questions just get in touch. 
Thanks.

Postage: RMSD by 1pm 
Payment: Bank Transfer. No Returns 

If so, then why when Germany asked to repatriate it's gold, was it told it would take up to 7 years to get it back from the US and when the first shipment arrived the serial numbers didn't match anything on Germany's manifest sheet of serial numbered bars? 
I'm genuinely interested to know, I like @HerefordBullyun don't believe for a minute that the US has the gold it says it has, be that for themselves or others. It's been sold off or leant out to to other countries so many times, that's it's in effect gone.

It's why the UK goes to the high courts to stop smaller countries repatriating their gold. They don't have it, or only have a portion of it and when the bluff is called and all countries ask for it back, then the king with no clothes will be revealed.

Countries used to use gold for international trade settlements, British empire Pounds (Sovereign gold coins) and 400 oz average bars. London was the hub and physically moved bars between different country cages in reflection of that. Since the US dollar was transitioned to paper dollars were instead moved, electronically. The US strives to keep the dollar aligned to gold as that better stabalises international trade. It's not good if one day something earns/costs $10, and the next it earns/cost $5, or $15. But that's not a direct peg, rather a channel range, that the US manages by buying or selling gold to realign it to the dollar. The US treasury hold 8000 tonnes of gold, and lends that to the Fed at a $42.222/oz rate, so at $2111 market price of gold the Fed has a 50x leverage factor, which in turn it might use to buy or sell leveraged gold such as Options/Futures (there's 123 times more paper gold than physical gold). So the Fed in effect at a $2111/oz price have over a 6000x leverage rate on each ounce of gold and have access to up to 8000 tonnes of gold for that. And if the dollar weakens/price of gold increases, so does that leverage factor (fail safe).