Just a little missunderstanding ...

BitGOLD is not backed by actual gold. Nor BitUSD by USD.

All BitAssets are baked by 200% of their value in BTS.

BTS is the collateral used to back the asset.

In the case of gold, every BitGOLD is back with 200% of its gold value in BTS. No fractional reserve, always fully backed.

That's MUCH more interesting this way because, the most BitAsset are created and used, the more BTS are locked in collateral. That shrink a lot the BTS supply creating higher buying pressure.