Quite straightforward: resolves to yes if there are 50 or more unique traders on this question by the end of this month PST.

Again: unique traders. This is the count displayed near the market title.

For context, these resolved to yes:
https://manifold.markets/DevonFritz/will-this-question-have-40-traders
https://manifold.markets/DevonFritz/this-question-have-29-traders-by-ju
https://manifold.markets/DevonFritz/this-question-have-32-traders-by-ju