Lots of markets on whether or not he will, none on whether the legal principle will withstand judicial scrutiny! Some context here, where like almost all articles on the topic the wording weasels out of giving any probabilistic sense of the action surviving court challenges.

N/A if the Biden administration does not invoke the 14th Amendment to justify issuing debt exceeding the debt ceiling.

YES if the 14th Amendment is invoked, and courts rule the action unconstitutional or otherwise outside the powers of the executive branch.

NO if the 14th Amendment is invoked, and courts rule in favor of the Biden administration, or no challenge is brought because of lack of standing or any other reason.

I will wait to resolve until there's no reasonable chance for appeals remaining, eg SCOTUS gives a ruling or remands to a lower court.