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Polymarket Up-or-Down Crypto Markets, Explained

What Polymarket's Up-or-Down crypto markets are, how 5m, 15m and 4h timeframes resolve, how pricing maps to probability, and what order book data looks like for them.

By polyReplay team

Quick answer: Polymarket Up-or-Down markets are short-dated prediction markets that ask whether a crypto asset like BTC or ETH will be higher or lower at the end of a fixed window — typically 5 minutes, 15 minutes, or 4 hours. You buy UP or DOWN shares priced between $0 and $1; the price is the implied probability, and the winning side settles at $1.

How an Up-or-Down market works

Every market has a start time, an end time, and a reference asset. The question is simply: will the price be up or down when the window closes?

  • You buy shares in the UP outcome or the DOWN outcome.
  • Each share trades between $0.00 and $1.00.
  • At resolution, the winning outcome's shares are worth $1.00 and the losing outcome's shares are worth $0.00.

So if you buy UP at $0.40 and UP wins, you make $0.60 per share. If it loses, you lose your $0.40.

Price = probability

Because the payout is a fixed $1, the price of a share is the market's implied probability of that outcome:

| UP price | Implied chance of UP | DOWN price | |---|---|---| | $0.50 | 50% | $0.50 | | $0.62 | 62% | $0.38 | | $0.85 | 85% | $0.15 |

UP and DOWN prices sum to roughly $1 (minus a small spread). This is what makes prediction markets so useful as data — the price is a continuously-updated, money-backed probability estimate.

The timeframes: 5m, 15m, 4h

Polymarket's crypto Up-or-Down markets come in several windows:

  • 5m — ultra short-term; dominated by spot momentum and microstructure.
  • 15m — short-term; a bit more room for mean reversion.
  • 4h — longer horizon; more macro, wider price ranges.

Shorter windows behave very differently from longer ones, which is why researchers usually study them separately.

What the order book looks like

Like any CLOB market, each outcome has a two-sided order book: bids (buyers) and asks (sellers) resting at various prices. Two levels of detail matter:

  • L1 (top of book) — just the best bid and best ask. Enough to know the current price and spread.
  • L25 (depth) — the top 25 levels on each side, with the size resting at each. This lets you model how far a large order would push the price and what slippage it would pay — essential for realistic backtesting.

polyReplay records L25 depth for every crypto Up-or-Down market tick-by-tick, at sub-150ms intervals, across 100+ days of history, so you can reconstruct the book as it looked at any past moment.

Why join with Binance spot?

An Up-or-Down market is a bet on the underlying asset, so the most important context is the spot price of that asset over the same window. polyReplay joins every market with second-resolution Binance spot data, so you can line up the prediction-market price against the actual asset price tick-for-tick — the foundation for studying price discovery, lead/lag, and edge.

Where to get the data

Frequently asked questions

What are Polymarket Up-or-Down markets?

Up-or-Down markets are short-dated Polymarket prediction markets that ask whether a crypto asset (such as BTC or ETH) will be higher or lower at the end of a fixed window — for example the next 5 minutes, 15 minutes, or 4 hours. You buy shares in the UP or DOWN outcome; the winning side settles at $1 and the losing side at $0.

How does pricing work on Polymarket?

Each outcome share trades between $0 and $1, and the price is the market's implied probability of that outcome. An UP share at $0.62 means the market thinks there's roughly a 62% chance the asset closes higher. The UP and DOWN prices sum to approximately $1.

What does L25 order book depth mean?

L25 means the top 25 price levels on each side of the order book — the 25 best bids and 25 best asks, with the size resting at each. It's deeper than L1 (just the best bid and ask) and lets you model how a larger order would move the price and what slippage it would incur.

How are Up-or-Down markets resolved?

At the end of the window the underlying reference price (for crypto, typically a spot index) is compared to the start price. If it's higher, UP wins and UP shares pay $1; if it's lower or equal, DOWN wins. polyReplay records the resolved outcome alongside the full order book and Binance spot history for each market.