The problem with picking a venue

There is no single gold price. London, New York, Shanghai and a dozen electronic venues all publish one, and on a busy second they can differ by more than a typical spread. If we settled on "the market price", we would be choosing which market after seeing your order, whether we meant to or not.

What we do instead

We pick one source, name it on every page that shows a price, and store its raw quote either side of each settlement. The choice is made once, in public, before any order exists. That is the difference between a rule and a discretion.

Why a bank feed

A bank publishes a two-way price it will actually deal on, which means the number is not just an index: it carries a spread that somebody is willing to trade. That makes it a fairer settlement basis than a synthetic index assembled after the fact.

The cost of this choice

One source is one point of failure. When it stops, we void the affected orders rather than substitute a different feed mid-flight, because switching sources silently would make the audit record unverifiable.