It is backed by gold it's backed by the productive wealth of those who choose to be part of the ledger.

If my memory serves Cypher backed Bitcoin with gold by using the dollar as a proxy. Even the likes of Schiff are backing Bitcoin with gold, they're using BitPay as a proxy.

Backing with gold is an idea whose time had gone, Bitcoin is backed by much more ultimately it's faith in the maths that governs the ledger.