I'll add one more reason I don't think we're in a gold bubble: as long as countries around the world continue devaluing their currencies, the nominal price of gold will continue to rise. While it's possible that the inflation-adjusted price of gold could fall, I can't imagine that happening in an environment where fiat currencies globally are being debased. I should say that this isn't just true for gold, but for any hard asset that hasn't seen an explosion of supply (like apartments in Nevada or China for example).

When central banks worldwide stop printing and start raising interest rates, that's when I'll start scrutinizing further accumulation...