No, you’d remark that your house has appreciated in value over the past 20 years. But you wouldn’t have realized any of that gain until you sold the house - the point being that the realization is the actual taxable event, which is why it matters from the pedantic technical accounting POV. The fact that you turned around and bought another house just means you’re doing something new with your realized gains. Now you have a new cost basis. Maybe that’s what you’re saying with “unrealized gain” though.

Sure in the spirit it's an unrealized gain but wouldn't the tax man consider it a realized $500K capital gain? seemingly this is would be the more appropriate way of categorizing it?

No but I read the article and that was the way it described the gain.

It's more that the english ain't parsing, for some at least.

The mining.com quote is classic weasel phrasing, seemingly meaningful yet disturbingly ambiguous:

  Due to rising gold prices, the move helped the bank to generate a capital gain of 13 billion euros ($15 billion), bringing it to a net profit of 8.1 billion euros for the 2025 financial year after a net loss of 7.7 billion euros in 2024.

So, the move helped the bank generate ...

Just as, say, one guy helped four others push a car back up on the road.

We've been given, accurately or not .. likely true, figures on how the bank did over a period, we've also been told the gold movements helped with that ... so they almost certainly kicked in at least $1.

Other costs? Deviations in the actual figures from the estimates we're using here? 100 is not a million miles away from 129.

They purchased 129 tons of gold in Europe. Their asset position did not change: they converted cash to gold of the same value.

They then sold the 129 tons gold in the US vaults for $16 billion. That gold was originally purchased I'm guessing many decades ago for $1 billion. The have a book profit of $15 billion and still have 129 tons of gold.

They captured some of the appreciation in gold value as a realised profit on their books.

Their balance sheet did not change, just their income statement

What I was trying to get at is that there are other ways to update asset valuations besides daily (market-to-market) and once (price paid) – those are just the extreme ends of a spectrum. What makes sense really depends on the asset class and how long you're holding the positions. As for "It's the rules", I'm aware that there are strict accounting rules for companies and regular banks, but do those really apply to the central bank in the exact same way? (A central bank typically operates on a much longer time scales.)