Overview

BOOKIE is a stock prediction market on Robinhood Chain (chain id 4663). Every market asks one yes-or-no question about a real stock price at a set time, for example "Will NVDA print above $215 after Friday's bell?". You can do one of two things:

Bet. Buy YES or NO shares with USDG. A winning share pays exactly 1 USDG. A losing share pays nothing. You can sell shares back to the pool any time before expiry.
Be the house. Deposit USDG into the house pool. The pool takes the other side of every bet in every market, prices each bet with pm-AMM, and keeps the fees.

Markets are opened by the operator, one per feed, strike and expiry, each funded from the house. A market opens at the price the Gaussian model gives from the feed's latest print, so a strike far above the stock opens cheap for YES. There is no judge and no reporter. Each market is settled by a Chainlink stock feed that already runs on Robinhood Chain, using the first price the feed prints at or after the market's expiry. See the print rule.

How a bet moves

 You                Market             House pool (pm-AMM)      Chainlink feed
  |  100 USDG on YES  |                        |                       |
  |------------------>|  mint 100 YES + 100 NO |                       |
  |                   |----------------------->|  price on the curve   |
  |   YES shares      |<-----------------------|  keeps NO + the fee   |
  |<------------------|                        |                       |
  |                   |      first print at or after expiry            |
  |                   |<-----------------------------------------------|
  |  1 USDG per       |                        |                       |
  |  winning share    |                        |                       |
  |<------------------|                        |                       |

What you see in the app

Number	What it means	Unit
YES price	What one YES share costs right now. It is also the market's odds that YES wins.	USDG per share, shown in cents
Shares	How many shares your stake bought. Each pays 1 USDG if your side wins.	shares
Last print	The newest price the market's Chainlink feed has published.	USD
Printed	How long ago that price was published.	time
House pool	All USDG deposited by the house, across every market.	USDG
Fees earned	Fees paid by bettors into the house.	USDG
Expected loss	What the pricing model expects the house to lose to better-informed bettors so far.	USDG

Where BOOKIE stands

BOOKIE runs on Robinhood Chain mainnet. The Bookie contract is 0x878d302a3093b432c6Fb174ae536cBED73bA1fEd and its fee burner is 0x713984395E4f965DE3784AFcF5f94Be18cd495AB. Every price, odds line and house number on the site is read from the chain.

Credit

pm-AMM is from "pm-AMM: A Uniform AMM for Prediction Markets" by Ciamac Moallemi and Dan Robinson (Paradigm, November 2024). BOOKIE did not invent it. See pm-AMM math.