France pulls last gold held in US for $15B gain

https://www.mining.com/france-pulls-last-gold-held-in-us-for-15b-gain/

Is anyone here actually reading the article? Yes, they really made a gain of $15B:

> But instead of refining and transporting the gold, it opted to sell the bars and purchase new bullion in Europe. […] Due to rising gold prices, the move helped the bank to generate a capital gain of 13 billion euros ($15 billion),

This doesn't make sense. If they first sold the bars held in the US, then the gold prices rose, then they bought gold in Europe, how the hell did that amount to a capital gain of $15b? How exactly do prices rising over the course of the process lead to these $15b?

First thought: Maybe they bought the gold first? Or the gold price was at a temporary high when they sold it?

Second thought: The numbers don't seem to check out: 129t are 4,147,456.307 troy ounces (1 troy ounce = 31.1034768 g). The total gains of 15e9 USD would thus correspond to gains of $3,616.68 per troy ounce, which seems excessively high, given that today's gold price is at ~$4,712. Even if they sold everything at the current all-time high of $5,589.38 on January 28 (and that's a big if), they would have had to buy for not more than $1,972.70, a price we last had in fall 2023.

They must have had an exceptional crystal ball!