I'm referring to this market.

Which has these rules:

This market will resolve to "Yes" if OpenAI's GPT-4 has 500 billion or more parameters when released. Otherwise, this market will resolve to "No".

This market covers how many parameters GPT-4 has at the time of its initial release, and will resolve based on that number regardless of whether that figure is later increased or decreased.

If GPT-4 is not released by December 31, 2023, 11:59:59 PM ET, this market will resolve 50-50.

GPT-4 refers to a product that is explicitly named GPT-4, or is a successor to GPT-3 in the way that GPT-3 was a successor to GPT-2; it cannot be branded as GPT3.5 or a version of GPT-3.

The primary resolution source for this market will be official information from OpenAI, however a consensus of credible reporting (including corroborating statements from employees of OpenAI where available) may also be used.

This market was created in response to @MarcusAbramovitch's comment here:

In a very similiar market on Manifold. @Jacy asks how this is compatible with Polymarket's current price of 56%.

Let's find out! This resolves based on the finalized result of the Polymarket question, which is due to close at the end of the year. Polymarket works by a system called UMA, where a resolution can be proposed, and then is either disputed or finalized.

I have left an "other" option for unknown unknowns, but I think I have covered every scenario with the other answers. Please let me know if there is another possibility I should add.