RizonWhat is a horizon contract?
A binary on a number that always pays 2×. The order book moves the strike, not the price, so every contract trades at 50/50. How it works, with examples.
Short answer: A horizon contract is a binary contract on a number (a price, a seat count, a rate or a date) that always pays a fixed 2×: you take Higher or Lower, and you win if the number finishes on your side of the strike. Its order book quotes strikes instead of prices in cents, so the price never moves and every contract trades at 50/50, around the market's median. The horizon is rolling (each contract expires a fixed time after its own fill: 15 seconds to 7 days on Rizon) or fixed (every contract settles on one date or result); in a date market, the number is itself a date.
Rizon is an exchange for horizon contracts, played with practice money. This guide defines the contract, the three kinds of horizon, and how it differs from the event contracts sold on Polymarket and Kalshi. The manifesto makes the case for why we think prediction markets will work this way.
The contract
| Part | What it is |
|---|---|
| The number | Anything with a value at a known time: Bitcoin's price, Republican House seats, the Fed's upper bound, the day something happens |
| Strike | The level the number has to finish above (Higher) or below (Lower). The order book quotes it |
| Side | Higher wins above the strike, Lower below it |
| Payout | 2× your size if you win, nothing if you lose |
| Horizon | When the contract expires: a fixed time after your fill (rolling), or one date for everyone (fixed) |
| Push | Both sides get their size back, which can only happen where the number can land exactly on a strike |
An example: $100 on Higher than 196.5 on Rizon's Republican House seats market (HOUSE-R-2026) pays $200 if Republicans win 197 seats or more, and nothing if they win 196 or fewer. A seat count can't land on 196.5, so that contract can't push. Bitcoin's strikes are whole dollars, and the price can finish exactly on one; then both sides get their size back.
The most a contract can lose is your size, and the most it can make is your size again.
The book quotes strikes, so every contract is 50/50
An event contract fixes the question ("Will Republicans win 195–199 seats?") and lets the price float between 0¢ and 100¢. A horizon contract fixes the price (2×, the same as buying a $1 contract at 50¢) and lets the strike float. The book works like a futures book whose price is the strike: Higher orders are bids, Lower orders are asks, and they meet where traders disagree about which side is ahead. That's the strike the market sees as 50/50, its median. The midpoint of the best bid and the best ask is the market's forecast of the number, in the number's own units: seats, percent, posts, a date.
Why fix the price there: a better forecast is worth the most at 50/50. What a forecast edge earns is roughly that edge times the density at the strike, and the density is highest in the middle of the distribution. Event venues price most of their markets far from the middle: of 173 prices we recorded on the Polymarket and Kalshi markets that Rizon's markets replace on Oct 29, 2026, 98 were under 10¢ or over 90¢ and 5 were between 40¢ and 60¢. The arithmetic is in Why every market on Rizon is 50/50, and how strikes and cents convert is in Strike vs probability.
Three kinds of horizon
Rolling. Each contract expires a fixed time after its own fill, on the first whole second at least that far on: a fill at 15:24:41.3 on a 1-minute market expires at 15:25:42. Every trader gets the full horizon, whenever they arrive, and fills in the same second share one expiry. Rolling fits numbers with a live feed: Bitcoin over 15 seconds, 1 minute or 5 minutes; gold over 5 minutes, 15 minutes or 1 hour; claude.ai's and Polymarket's uptime over the next 7 days.
Fixed. Every contract expires at one moment, and trading stops at a set close or when the result is known (Rizon halts the House market once every race is called). A fixed market settles on its result from a named source, not on a timer, and a result that comes in early settles every open contract at once. Two are void, with everyone refunded, if their event never happens: Anthropic's first-day market cap if it hasn't listed by the end of 2027, and predict.fun's FDV if there's no token by then.
Date. A fixed market whose number is a date: the day something happens, written as a Julian Day Number (JDN), the day count astronomers use (Oct 29, 2026 is JDN 2,461,343). Strikes sit on the halves between day numbers, which are the midnights between days, so "Higher than Nov 15" means Nov 15 or later and Lower means Nov 14 or earlier, and a date market never pushes. A contract expires at its strike's midnight or the market's deadline, whichever comes first, plus 2 days for the source to report. If the event hasn't happened by the deadline, Higher wins. The US–Iran post works through one.
| Kind | Expires | Settles on | Can it push? |
|---|---|---|---|
| Rolling | Fill time plus the horizon, on the next whole second | The feed's value at expiry | Yes, where the value can equal a strike (Bitcoin, gold) |
| Fixed | One moment for every contract | The result, from the named source | Not on seats, counts, rates or yields: strikes sit between values |
| Date | The strike's midnight or the deadline, plus 2 days | The day the event happens | No |
More on choosing between them in Fixed vs rolling horizons.
What's listed
The market list as decided on Oct 29, 2026 (the markets panel in the app is the live list):
| Category | Market | Id | Horizon |
|---|---|---|---|
| Crypto | Bitcoin | BTC-15s, BTC-1m, BTC-5m | Rolling: 15 s, 1 m, 5 m |
| Crypto | predict.fun FDV, a day after launch | PREDICT-FDV | Fixed |
| Commodities | Gold (PAXG) | GOLD-5m, GOLD-15m, GOLD-1h | Rolling: 5 m, 15 m, 1 h |
| Politics | House seats: Republicans | HOUSE-R-2026 | Fixed |
| Politics | Senate seats: Republicans | SENATE-R-2026 | Fixed |
| Politics | House popular vote margin | HOUSE-VOTE-2026 | Fixed |
| Politics | US–Iran ceasefire: the next US strike | IRAN-STRIKE | Date |
| Economy | Fed rate, end of 2027 | FED-2027 | Fixed |
| Economy | 10-year yield, highest close by Dec 31 | UST10Y-MAX-2026 | Fixed |
| Tech | Anthropic IPO: date | ANTH-IPO-DATE | Date |
| Tech | Anthropic IPO: first-day market cap | ANTH-IPO-CAP | Fixed |
| Tech | Next Fable model | FABLE-NEXT | Date |
| Culture | Elon Musk's posts this week | ELON-W-2026-10-30, a new id each week | Fixed |
| Uptime | claude.ai uptime | CLAUDE-UP-7d | Rolling: 7 days |
| Uptime | Polymarket uptime | POLY-UP-7d | Rolling: 7 days |
Horizon contract vs event contract
| Event contract (Polymarket, Kalshi) | Horizon contract (Rizon) | |
|---|---|---|
| What you buy | Yes or No on one bucket, date or strike | Higher or Lower on the number |
| Price | Floats from 0¢ to 100¢ | Fixed: pays 2×, like 50¢ for $1 |
| What moves | The price | The strike |
| One number becomes | Many markets: 10 for House seats on Polymarket, about 30 for Elon Musk's weekly posts | One book |
| Where prices sit (Oct 29, 2026) | 98 of 173 under 10¢ or over 90¢ | 50/50 by construction |
| What a win pays | $1 a share | 2× your size |
| The forecast | Add up the buckets | The book's midpoint |
| Time | Blocks on the clock for crypto; one date for events | From your fill, or one date for events |
FAQ
What is a horizon contract in simple terms?
A contract that pays 2× your size if a number finishes on your side of a strike, Higher or Lower. The market moves the strike rather than the price, so every contract is priced at 50/50.
Why is it called a horizon contract?
Because it's defined by its horizon, how far ahead the number is measured: a fixed time from your own trade (15 seconds to 7 days on Rizon) or a date everyone shares. The name Rizon comes from "horizon" too.
Is a horizon contract the same as an up/down market?
They're related. An up/down market fixes the strike at the opening price of a window on the clock and lets the price in cents drift; a horizon contract fixes the price at 2× and lets the book set the strike, from your fill or for an event date.
What is a Julian Day Number?
A whole-number count of days that astronomers use: Oct 29, 2026 is 2,461,343. Rizon's date markets quote dates this way, with strikes on the halves between them, which are the midnights.
Is Rizon real money?
No. Rizon is a paper exchange: practice money, no deposits. The other venues' prices quoted here are Polymarket's and Kalshi's, recorded on Oct 29, 2026.