When are stock prices updated in Apple Numbers?

This question has appeared multiple times, but I thought I'd check again. When using the Stock function in Apple Numbers, has anyone figured out when stock prices are actually updated?

Some earlier responses have suggested that prices are updated 15 minutes after market close. This has not been my experience, plus it begs the question "Which market?". If, for example, you track the following stocks in Numbers, each of which is listed on a different exchange and in a different time zone, when is each stock price updated?

Pls note that I am not trying to alter the behavior of the Stock function, I'm just trying to understand how it works. Thx.