Gold

The decision on what type of gold exposure to give yourself is really personal preference.

In terms of liquidation, out of the things you listed above a gold company is going to be the most liquid in most all situations. Someone who owns a gold bar cannot sell it as quickly as someone who owns gold stocks, as it takes a simple click of a button to sell shares (in most cases, if the company has liquidity.)

But in this case, a gold mining company is almost always going to be more volatile than the price of gold. So for example, if gold falls 2%, the miner will typically fall more than 2%. Not always, but most of the time it will be more volatile than the underlying commodity it depends on.

There are also plenty of ETFs that can expose you to physical gold, saving the need to physically buy it but we do see the reasoning of investors wanting to hold actual gold.