David Wallace is a prominent physicist and philosopher who advocates many-worlds interpretation of quantum mechanics. 

I think he is wrong in claiming that "decoherence implies branching" in his book, for reasons summarized in this youtube video: 

This market resolves "Yes", if Wallace publicly admits that his claim is problematic. This market resolves "No", if I publicly admit that my own criticism is problematic.

If neither happens, you could still profit by predicting the traders' opinions of who is right.

https://manifold.markets/ttoe/are-feldbrugge-lehners-turok-wrong

https://manifold.markets/ttoe/are-rovelli-and-vidotto-wrong-about