A large, solid gold asteroid, brought to Earth, would depress the market. Keeping it in orbit and mining is in small amounts at a time is the better choice. Plus keeping it’s existence a secret, is imperative. Just the knowledge that it exists would depress the market, although not as bad as its physical presence on Earth.
Like Debeers hoarding diamonds to keep the market stable, you would have to do the same with the gold you thought would make you rich, but in reality would make everyone else poorer................
True, good point.