This whole thing is just a negotiating tactic, no one actually expects the US to default. Except maybe the media who is greatly enjoying the extra views from concerned viewers.
That is the definition of a Black Swan. US political parties have audaciously risked the foundations of democracy for the advancement of their own political agendas. It is my forecast that the Speaker of the House's political fragility in ensuring adherence to any concurred deal, may well manifest as the Black Swan, potentially precipitating a default.
Read the comments with this in mind and see how people just have such different worldviews.
bet you 50 bucks it won't happen