William, or anyone else for that matter, cannot abdicate until after they ascend to the throne. You can't remove yourself from the line of succession.

@JoshuaWilkes Really? What did Harry just do? The basic idea behind the question is the monarchy ends with Charles. Obviously the wording of the resolution needs work.

@whit If, hypothetically speaking, Charles, William and William's children died in a helicopter crash tonight, Harry would become King. He has left the 'working royals', but he can't leave the line of succession.

@whit I think the resolution criteria could be 'Market resolves to YES if William does not die or the monarchy is not abolished prior to the death of King Charles III'

if William does not absconed or the monarchy is not abolished

I think you mean "if William does not abdicate and the monarchy is not abolished"? This doesn't quite seem like the same question as whether he's crowned, e.g. William could die before or around the same time as Charles, or maybe he could become ineligible in some other way, I'm not sure how that works.