As counterintuitive as it may initially seem, Treasuries are most likely the safe haven. The US will pay P&I on their debt and furlough discretionary spending. Gold will rise but more likely due to devaluation of the dollar. A downgrade will most likely hit equities the hardest, thus causing a run to Treasuries.
Could there be a run to Bitcoin? Sure. We're in some unprecedent water, no one really knows what will happen. But if I was putting down a wager, it'd be on Treasuries.
thats certainly a good bet. in 2008, paradoxically UST's and USD's rose while everything else tanked including gold but not as bad as everything else. this may happen again as i think the equity mkts have topped. but one things for sure, relationships that held in the past may not necessarily hold in the future and there will be surprises.
could btc be the wild card?