The Patient Philanthropy Fund says that "When the PPF hits $10m, the investment strategy will be updated and expanded to include active and mission-aligned options and additional research partners will be added." So, to resolve this question, in january 2030 I'll simply check and see if the PFF has hit this milestone yet.

For markets about other cause-area-candidates (like approval voting and climate geoengineering!), check out the "New EA Cause Area?" tag!