Subreddits for Forecasters

FAQ

What are Prediction Markets subreddits?

Online communities for forecasting future events, debating prediction markets, and sharpening your probabilistic thinking skills. This page focuses on communities hosted on Reddit, so you can compare their size, features, reviews, and access requirements in one place.

What are the most popular prediction markets subreddits on Hive Index?

r/forecasting, r/predictionmarkets, r/cognitivebias, and r/SampleSize are among the most popular prediction markets subreddits in the Hive Index directory of communities, based on visitor interest on Hive Index. This is not a universal quality score. You can also compare listings by review scores, member counts, and listing age on Hive Index.

Are prediction markets subreddits free to join?

All 6 listings in the Hive Index directory of communities are marked as free to join. Popular examples include r/forecasting, r/predictionmarkets, r/cognitivebias, and r/SampleSize. Access rules can still change on the community side.

What features do these subreddits include?

Forum is the most common feature (100% of listings).

How large are prediction markets subreddits?

Hive Index lists 6 prediction markets subreddits in the Hive Index directory of communities. The largest include r/futurology (21.7M members), r/SampleSize (271K members), and r/rational (29K members). Median reported size is about 21K members (6 listings with member data). We only have a handful of listings so far, so treat these numbers as directional.

How do I join a Prediction Markets community on Reddit?

Browse listings in the Hive Index directory of communities, open a community that fits your needs, and follow its join link to Reddit. Some communities may require an application or paid membership, which is shown on the listing when known.

How do I grow my Prediction Markets community on Reddit?

List your Prediction Markets community on Reddit for free on Hive Index to reach people already searching for Prediction Markets subreddits. Paid promotion can feature your community more prominently across relevant pages and send more qualified visitors to your listing.

How does Hive Index collect and rank listings?

Listings are submitted by community builders and researchers, reviewed for topic relevance, and updated with platform, feature, member, review, and traffic data where available. Member counts are approximate. Popular reflects visitor interest in the Hive Index directory of communities, with richer profiles breaking ties. Ratings, Largest, and Newest use review scores, reported member counts, and listing age instead. These listings in the Hive Index directory of communities were last updated 10/14/2026.