Meet Sidemarket — A calm watchlist for prediction markets. Bring your own EV
Sidemarket is the watchlist + decision tool for prediction-market traders on Kalshi and Polymarket.
Finance
Sidemarket
A calm watchlist for prediction markets. Bring your own EV.
Every feature, from the first launch.
No account, no login, no cloud. Everything runs on your device and works fully offline — nothing in this post is hidden behind a wall.
What Sidemarket does
Sidemarket is the watchlist + decision tool for prediction-market traders on Kalshi and Polymarket. It doesn't connect to your account, doesn't place trades, and doesn't broadcast your positions. It's the spreadsheet you'd build yourself if you had the patience: a watchlist of markets you care about, an EV calculator, a base-rate library for the categories you trade, and a journal of the trades you've actually made.
What's in v1:
— Watchlist: paste a market URL or pick from 40 bundled categories (NFL Super Bowl winner, US recession 2026, BTC > $200K, Fed rate path, election outcomes...). Track your perceived fair-value vs. market price, side-by-side. — EV calculator: enter your edge, the offered price, and your bankroll. Sidemarket computes EV, Kelly stake, and a half-Kelly recommendation. The math is open-source classic — no black box. — Base-rate library: 60 hand-curated base rates with sources (incumbent advantage in US presidential, March Madness #1 seed wins by round, Fed action implied by Fed Funds futures, etc.). The base rate is the only edge most retail traders have. — Trade journal: log every position with entry price, your fair-value at entry, exit, p/l. No broker integration — you copy from your account once. — Lessons: a learned-rules log. Each time a trade closes badly, log the lesson in one sentence. The journal is the moat.
Sidemarket is not connected to Kalshi or Polymarket. It's a calm second-screen.
Free. Optional Sidemarket Pro ($19.99/yr) adds the journal export, custom base-rate entries, and the multi-bankroll mode.
A look inside
Tap any screenshot to open the full-resolution version.
What's inside
- Watchlist — Cross-platform market watchlist.
- EV + Kelly calculator — Open math, no black box.
- Base-rate library — 60 curated base rates with sources.
- Trade journal — Manual log, lessons attached.
Why we built it
Kalshi $22B val / $178B annualized volume. Polymarket relaunched US Nov 2025. Bloomberg covered the category as a real asset class. AI agents are 30% of Polymarket trades — retail traders can't compete on speed but can compete on patience + base rates. The journal/calculator/watchlist combo doesn't exist as one calm a…
What makes it different
Sidemarket is the only iOS tool that combines: (a) cross-platform watchlist for Kalshi + Polymarket markets, (b) classic EV + Kelly calc with open math, (c) base-rate library curated for the categories these markets trade, (d) trade journal as the core surface (not an afterthought). LayerHub is AI-agent infrastructure…
Who it's for
Freelancers, contractors, and small-business owners who want their numbers right at tax time without renting a SaaS to do it.
In one line: A calm watchlist for prediction markets. Bring your own EV.
Try it
See the Sidemarket app page for the full feature list, the info table, and support links.
Use Sidemarket, found a bug, or have a feature request? Comments are open below — anonymous is fine.
0 comments
No comments yet — be the first.
Leave a reply
Sign in with Google to join the conversation. We require a quick sign-in to keep comments spam-free.
Sign in with Google to comment