The milestone was reached Friday, when the precious metal’s spot price surpassed $2,500 per troy ounce, an all-time high. With gold bars typically weighing about 400 ounces, that would make each one worth more than $1 million.

There are some nuances to the figure. While gold bars in the London market — the global center for trading the precious metal — normally weigh about 400 troy ounces, they can contain 350 to 430 ounces of pure gold, according to the London Bullion Market Association. It’s also possible for individuals to buy much smaller, more affordable bars such as those sold by Costco.In the first half of this year, central bank net purchases of gold stood at 483.3 tons, equivalent to almost 40,000 bars, according to a Bloomberg calculation using figures from consultancy Metals Focus. It’s one of the factors that has supported the precious metal’s blistering rally so far this year, along with expectations of looser monetary policy from the US Federal Reserve.