lucyd

Lucyd vs Polymarket and Kalshi for Bitcoin Up/Down markets

· Lucyd

Short Bitcoin Up/Down markets have become one of the most traded formats in prediction markets. The question is always the same: will BTC be higher at the end of the round than at the start? Polymarket and Kalshi both list these markets. Lucyd is built only around them.

Here is how the three compare, so you can pick the venue that fits how you trade.

Round lengths

  • Lucyd: 5 minutes, 15 minutes, 30 minutes, 1 hour, 4 hours and 1 day. Every series runs back to back, so there is always an open round of every length.
  • Polymarket: short crypto Up/Down markets, including 5-minute and 15-minute Bitcoin rounds, plus longer ones.
  • Kalshi: short crypto markets with 15 minutes as the shortest round.

If you want the whole range from 5 minutes to a day in one order book interface, Lucyd covers it.

What decides the result

A short round is only as fair as the price it settles on.

Lucyd settles every market on the Pyth BTC/USD price: the first Pyth price published at the round's end time, read and checked on chain by the resolver contract. If no price arrives within the settlement window, the market is voided and everyone gets their money back instead of a guessed result. The strike is the Pyth price at the start of the round. How settlement works.

Polymarket and Kalshi each name their own price source in the rules of every market. Read those rules before you trade: on a 5-minute round, a difference in the reference price matters.

Fees

Lucyd charges no trading fees while it runs on testnet, and trading needs no gas: the exchange settles fills on chain for you.

Polymarket has added taker fees on its short crypto markets, and Kalshi charges a fee per contract. Both publish their current schedules; on rounds this short, fees are a large part of the cost of trading, so compare them for your order size.

Access

  • Lucyd: any wallet, no account approval. Log in with email or a crypto wallet. Currently on the Ethereum Sepolia testnet with test USDC, so you can learn the format without risking money.
  • Polymarket: crypto wallet based, availability depends on your country.
  • Kalshi: a CFTC-regulated US exchange with identity checks and fiat deposits.

Bots, API and AI agents

Short rounds suit automated trading. Lucyd is open for it:

  • a public REST API for markets, trades, positions and trader stats, and a WebSocket order book feed (API docs);
  • orders signed with EIP-712 and sent over WebSocket;
  • an MCP server, so Claude, Cursor or any MCP agent can browse markets and trade in plain language: npx -y @lucyd/mcp (setup).

Onchain from end to end

On Lucyd, outcome tokens are ERC-1155 tokens in a ConditionalTokens contract, fills settle through the Exchange contract, and settlement runs on the Pyth price on chain. Contract code is public on GitHub. Winning tokens can be redeemed automatically, so payouts land in your wallet without an extra step.

Which one to use

  • You want the deepest liquidity in short crypto markets today: Polymarket.
  • You are in the US and want a regulated fiat venue: Kalshi.
  • You want every round length from 5 minutes to a day, Pyth settlement, no fees, and an exchange built for bots and AI agents, or you want to learn the format with test money first: try Lucyd.