Horizon contracts

A horizon contract is a binary contract on a number (a price, a seat count, a rate or a date) that pays a fixed 2× if the number finishes on your side of a strike, with the order book quoting the strike instead of a price, so every contract trades at 50/50.

You take Higher or Lower, and you risk your size to win your size. The market moves the strike, so the book's midpoint is a live forecast of the number itself, and one order book does the work of the dozen bucket markets an event venue would list.

Not to be confused with Horizon Trading Solutions, Horizon Protocol or Concord Horizon, which are companies. Here, "horizon" means how far ahead the number is measured.

Last updated: 3 November 2026

Definition#

A horizon contract has five terms.

At expiry, each side gets this back:

In options terms, it's a cash-or-nothing digital option whose premium is fixed at half its payout, traded on a central order book where the strike is the quoted variable. FX options desks make a similar inversion when they quote a 25-delta option and let the strike follow; a horizon contract is always the digital priced at 50%. It's fully funded: no margin, no leverage and no liquidation.

How the order book works#

The book works like a futures book whose price is the strike. Higher orders are bids and Lower orders are asks. A trader who buys takes the best ask and holds Higher at that strike; a trader who sells takes the best bid and holds Lower at that strike. The spread is in the number's own units: dollars, seats, percentage points, days.

The midpoint of the best bid and the best ask is the strike the market prices at 50/50, which is its median. That makes the book's midpoint a forecast you can read directly: "193 seats", "4.375%", "Nov 17".

These are Rizon's books on Nov 2, 2026 (paper money, quoted by open-source market-making bots):

An example: buying $100 on HOUSE-R-2026 takes the ask, so you hold Higher at 194.5. It pays $200 if Republicans win 195 seats or more and nothing if they win 194 or fewer. A seat count can't land on 194.5, so this contract can't push. Five worked trades go through the other kinds.

Why fix the price at 50/50#

A better forecast is worth the most at 50/50. A contract that pays $1 above a strike is worth P(X > K), and if your forecast sits a small distance δ above the market's, your edge in probability is about f(K) × δ, where f is the density at the strike. Density peaks near the median. For a normal distribution, knowing the median 0.2 standard deviations better than the market makes a 50¢ contract worth 7.9¢ more to you and a 3¢ contract 1.6¢ more, at about twice the Sharpe ratio.

Event venues price most of their contracts far from there. Of 173 prices recorded on Oct 29, 2026 on Polymarket and Kalshi markets on Rizon's questions, 98 were under 10¢ or over 90¢ and 5 were between 40¢ and 60¢. The arithmetic and its caveats are in why every market on Rizon is 50/50.

How to price one#

The fair strike is the median of the number at expiry: the level it's as likely to finish above as below. The price itself never changes, so the question a trader answers is whether a strike is on the right side of the median, and by how much.

Expected PnL per $1 of size is 2p − 1, where p is your chance of winning, and for an even payoff the Kelly fraction is the same number. On a live price over a short horizon the median is about spot, so the win chance follows from volatility: over one minute of Bitcoin in Sep–Oct 2026, a strike $10 below spot finished in the money 68.5% of the time. On an event, read the median off the bucket prices: on Oct 29, Polymarket's 10 buckets for Republican House seats implied 196.2. How to price a horizon contract works through both, with the cost of crossing the spread.

There's no fee on Rizon, so the only cost of trading is the spread: buying takes the best ask, a strike just above the midpoint, and selling takes the best bid. That's the cost on any order book. Polymarket and Kalshi also charge takers about 1.75¢ a share at 50¢, so at the same spread Rizon is cheaper by that fee. The spread is set by whoever quotes the book, and anyone can quote tighter.

Three kinds of horizon#

A rolling horizon contract has nothing to do with rolling a futures position forward: nothing is carried into a new contract. "Rolling" means the clock starts at your fill, so nobody arrives late to a window. More in fixed vs rolling horizons.

Compared with other contracts#

Full comparisons: vs event contracts, vs binary options, vs perpetual futures, vs fixed up/down windows and vs bucket markets.

Limits#

• It needs a number. A plain yes-or-no question with no count, level or date behind it stays an event contract.
• Lumpy outcomes have no 50/50 strike. When one value holds most of the probability, no strike splits it evenly: the Fed's December 2026 decision traded at 76.5¢ for a hike, so Rizon lists the end-2027 rate instead. Near-certain numbers leave the book one-sided, as on 1-day uptime.
• It runs to expiry. You can't sell a contract back, only hedge it by taking the other side.
• You can't trade a long shot. A 5¢ contract's large payoff doesn't exist here: every contract risks your size to win your size.
• A settlement can still be pushed. A contract that settles on a tradable price can be moved by a holder who trades the underlying at expiry. A rolling horizon at a fixed 2× makes the same push on the same position worth about 30× less than on a fixed 5-minute window, but the shorter the horizon, the less a push has to overcome.
• Rizon is paper money. Prices come from market makers and paper traders. They track real venues, but no real money backs them yet.

Where horizon contracts trade#

Rizon (rizon.markets) lists them, with practice money and a public API. Every market's live forecast is at rizon.markets/markets. As of November 2026 we don't know of another exchange that does.

Where the term comes from#

Rizon introduced the name in October 2026, and the manifesto makes the case for it. The parts are older: a fixed payout or nothing is a cash-or-nothing digital option, a book whose price is a level is a futures book, and a contract that starts at your own trade is how venue-priced products such as Binance's Event Contracts already work. What's new is putting them together: the price fixed at 50/50, and an order book, rather than a venue, setting the strike.

The open specification and reference code are on GitHub, so that anyone can list them, and the argument is in a working paper, Horizon Contracts: Quoting Binary Claims by Strike (doi:10.5281/zenodo.23888444). To cite this page: Rizon, "Horizon contracts", rizon.markets/horizon-contracts.

Guides#

• What is a horizon contract? The plain-English version.
• Horizon contract examples: five worked trades, from Bitcoin to the midterms.
• How to price a horizon contract: the fair strike, your edge and what a quote costs.
• How to make markets in horizon contracts: quoting strikes, with open-source code.
• Settlement manipulation in 5-minute markets: what the research found, and what rolling horizons change.
• Strike vs probability: converting between strikes and cents.
• The glossary: every term, with its own link.
• The specification: what makes a product a horizon contract, for anyone building one.

FAQ#

What is a horizon contract in one sentence?#

A binary contract on a number that pays 2× if the number finishes on your side of a strike, where the order book sets the strike rather than a price, so every contract trades at 50/50.

Is a horizon contract a binary option?#

By payoff, yes: it pays a fixed amount or nothing at expiry. It differs in the market around that payoff: the price is fixed, the strike comes from an order book rather than the venue, and the other side is another trader. See horizon contract vs binary option.

How is a horizon contract different from an event contract?#

An event contract fixes the question and lets the price float from 0¢ to 100¢. A horizon contract fixes the price at 50/50 and lets the strike float. See horizon contract vs event contract.

What is the fair price of a horizon contract?#

The price is fixed: you pay your size and a win pays 2×, the same as 50¢ for a $1 contract. What's fair or unfair is the strike, and the fair strike is the median of the number at expiry.

What do Higher and Lower mean?#

Higher wins if the number finishes above the strike and Lower wins if it finishes below. In the API they're the sides up and down, and in the book Higher orders are bids and Lower orders are asks.

What happens if the number lands exactly on the strike?#

It's a push: both sides get their size back. It can only happen where a value can equal a strike, such as Bitcoin's whole-dollar strikes. Seats, counts, rates and dates have strikes between their possible values, so they can't push.

Can you sell a horizon contract before it expires?#

No. It runs to expiry. You can hedge it by taking the other side, which leaves you flat outside the two strikes.

Can you lose more than your size?#

No. Your size is paid in full when you trade, and that's the most you can lose. There's no margin call and no liquidation.

What does it cost to trade a horizon contract?#

The spread, and nothing else on Rizon: there's no fee. Buying takes the best ask and selling takes the best bid, as on any order book. See how to price a horizon contract.

Can a horizon contract be manipulated at settlement?#

A holder can still trade the underlying at their own expiry. But a rolling horizon spreads expiries across time, so a short push reaches only a small slice of a position, and a fixed 2× caps what a win pays. Over 5 minutes, the same push on the same position is worth about 30× less than on a fixed window. See settlement manipulation in 5-minute markets.

Who created horizon contracts?#

Rizon named and listed them in October 2026, building on digital options and futures order books.

Is a horizon contract related to Horizon Trading Solutions or Horizon Protocol?#

No. Those are companies with Horizon in their names. A horizon contract is a type of contract, named for its horizon, how far ahead the number is measured. Rizon, the exchange that lists them, is also separate from the Rizon stablecoin app and the RIZON blockchain.

Where can I trade horizon contracts?#

On Rizon, with paper money and no signup. Real-money trading isn't available, and Rizon takes no deposits.