Gnosis Prediction Market Contracts Documentation¶

Collection of smart contracts for the Gnosis prediction market platform (https://www.gnosis.pm). To interact with those contracts have a look at (https://github.com/gnosis/pm-js).

Install¶

Install requirements with npm:

npm install @gnosis.pm/pm-contracts

Testing and Linting¶

Run all tests (requires Node version >=7 for async/await, and will automatically run TestRPC in the background):

npm test

Run all tests matching a regexp pattern by setting the TEST_GREP environment variable:

TEST_GREP='short selling' npm test

Lint the JS:

npm run lint

Compile and Deploy¶

These commands apply to the RPC provider running on port 8545. You may want to have TestRPC running in the background. They are really wrappers around the [corresponding Truffle commands](http://truffleframework.com/docs/advanced/commands).

Compile all contracts to obtain ABI and bytecode:

npm run compile

Migrate all contracts required for the basic framework onto network associated with RPC provider:

npm run migrate

Network Artifacts¶

Show the deployed addresses of all contracts on all networks:

npm run networks

Command line options for truffle can be passed down through NPM by preceding the options list with –.

For example, to clean network artifacts:

npm run networks -- --clean

Network artifacts from running migrations will contain addresses of deployed contracts on the Kovan and Rinkeby testnets.

Take network info from networks.json and inject it into contract build artifacts. This is done prepublish as well:

npm run injectnetinfo

Extract all network information into networks.json:

Be aware that this will clobber networks.json, so be careful with this command:

npm run extractnetinfo

Gas Measurements¶

Log gas measurements into build/gas-stats.json:

npm run measuregasstats

Documentation¶

There is a copy version hosted online at https://gnosis.github.io/pm-contracts/

Build docs with doxity:

scripts/makedocs.sh

Security and Liability¶

All contracts are WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.

License¶

All smart contracts are released under LGPL v.3.

Contributors¶

Stefan George (Georgi87)
Martin Koeppelmann (koeppelmann)
Alan Lu (cag)
Roland Kofler (rolandkofler)
Collin Chin (collinc97)
Christopher Gewecke (cgewecke)

CampaignFactory¶

contract CampaignFactory¶

Title:	Campaign factory contract - Allows to create campaign contracts
Author:	Stefan George - <stefan@gnosis.pm>

event CampaignCreation(address indexed creator, Campaign campaign, Event eventContract, StandardMarketFactory marketFactory, MarketMaker marketMaker, uint24 fee, uint funding, uint deadline)¶ ¶

Campaign public campaignMasterCopy¶

constructor(Campaign _campaignMasterCopy)¶ public ¶

function createCampaign(Event eventContract, StandardMarketFactory marketFactory, MarketMaker marketMaker, uint24 fee, uint funding, uint deadline)¶ public returns (Campaign campaign) ¶

Creates a new campaign contract

Parameters:	eventContract – Event contract marketFactory – Market factory contract marketMaker – Market maker contract fee – Market fee funding – Initial funding for market deadline – Campaign deadline
Return:	Market contract

Campaign¶

contract Campaign is Proxied, CampaignData¶

Title:	Campaign contract - Allows to crowdfund a market
Author:	Stefan George - <stefan@gnosis.pm>

function fund(uint amount)¶ public timedTransitions atStage(Stages . AuctionStarted) ¶

Allows to contribute to required market funding

Parameters:	amount – Amount of collateral tokens

function refund()¶ public timedTransitions atStage(Stages . AuctionFailed) returns (uint refundAmount) ¶

Withdraws refund amount

Return:	Refund amount

function createMarket()¶ public timedTransitions atStage(Stages . AuctionSuccessful) returns (Market) ¶

Allows to create market after successful funding

Return:	Market address

function closeMarket()¶ public atStage(Stages . MarketCreated) ¶

Allows to withdraw fees from market contract to campaign contract

Return:	Fee amount

function withdrawFees()¶ public atStage(Stages . MarketClosed) returns (uint fees) ¶

Allows to withdraw fees from campaign contract to contributor

Return:	Fee amount

CategoricalEvent¶

contract CategoricalEvent is Proxied, Event¶

Title:	Categorical event contract - Categorical events resolve to an outcome from a set of outcomes
Author:	Stefan George - <stefan@gnosis.pm>

function redeemWinnings()¶ public returns (uint winnings) ¶

Exchanges sender’s winning outcome tokens for collateral tokens

Return:	Sender’s winnings

function getEventHash()¶ public view returns (bytes32) ¶

Calculates and returns event hash

Return:	Event hash

CentralizedOracleFactory¶

contract CentralizedOracleFactory¶

Title:	Centralized oracle factory contract - Allows to create centralized oracle contracts
Author:	Stefan George - <stefan@gnosis.pm>

event CentralizedOracleCreation(address indexed creator, CentralizedOracle centralizedOracle, bytes ipfsHash)¶ ¶

CentralizedOracle public centralizedOracleMasterCopy¶

constructor(CentralizedOracle _centralizedOracleMasterCopy)¶ public ¶

function createCentralizedOracle(bytes memory ipfsHash)¶ public returns (CentralizedOracle centralizedOracle) ¶

Creates a new centralized oracle contract

Parameters:	ipfsHash – Hash identifying off chain event description
Return:	Oracle contract

CentralizedOracle¶

contract CentralizedOracle is Proxied, Oracle, CentralizedOracleData¶

Title:	Centralized oracle contract - Allows the contract owner to set an outcome
Author:	Stefan George - <stefan@gnosis.pm>

function replaceOwner(address newOwner)¶ public isOwner ¶

Replaces owner

Parameters:	newOwner – New owner

function setOutcome(int _outcome)¶ public isOwner ¶

Sets event outcome

Parameters:	_outcome – Event outcome

function isOutcomeSet()¶ public view returns (bool) ¶

Returns if winning outcome is set

Return:	Is outcome set?

function getOutcome()¶ public view returns (int) ¶

Returns outcome

Return:	Outcome

DifficultyOracleFactory¶

contract DifficultyOracleFactory¶

Title:	Difficulty oracle factory contract - Allows to create difficulty oracle contracts
Author:	Stefan George - <stefan@gnosis.pm>

event DifficultyOracleCreation(address indexed creator, DifficultyOracle difficultyOracle, uint blockNumber)¶ ¶

function createDifficultyOracle(uint blockNumber)¶ public returns (DifficultyOracle difficultyOracle) ¶

Creates a new difficulty oracle contract

Parameters:	blockNumber – Target block number
Return:	Oracle contract

DifficultyOracle¶

contract DifficultyOracle is Oracle¶

Title:	Difficulty oracle contract - Oracle to resolve difficulty events at given block
Author:	Stefan George - <stefan@gnosis.pm>

event OutcomeAssignment(uint difficulty)¶ ¶

uint public blockNumber¶

uint public difficulty¶

constructor(uint _blockNumber)¶ public ¶

Contract constructor validates and sets target block number

Parameters:	_blockNumber – Target block number

function setOutcome()¶ public ¶: Sets difficulty as winning outcome for specified block

function isOutcomeSet()¶ public view returns (bool) ¶

Returns if difficulty is set

Return:	Is outcome set?

function getOutcome()¶ public view returns (int) ¶

Returns difficulty

Return:	Outcome

EventFactory¶

contract EventFactory¶

Title:	Event factory contract - Allows creation of categorical and scalar events
Author:	Stefan George - <stefan@gnosis.pm>

event CategoricalEventCreation(address indexed creator, CategoricalEvent categoricalEvent, ERC20 collateralToken, Oracle oracle, uint8 outcomeCount)¶ ¶

event ScalarEventCreation(address indexed creator, ScalarEvent scalarEvent, ERC20 collateralToken, Oracle oracle, int lowerBound, int upperBound)¶ ¶

mapping (bytes32 => CategoricalEvent) public categoricalEvents¶

mapping (bytes32 => ScalarEvent) public scalarEvents¶

CategoricalEvent public categoricalEventMasterCopy¶

ScalarEvent public scalarEventMasterCopy¶

OutcomeToken public outcomeTokenMasterCopy¶

constructor(CategoricalEvent _categoricalEventMasterCopy, ScalarEvent _scalarEventMasterCopy, OutcomeToken _outcomeTokenMasterCopy)¶ public ¶

function createCategoricalEvent(ERC20 collateralToken, Oracle oracle, uint8 outcomeCount)¶ public returns (CategoricalEvent eventContract) ¶

Creates a new categorical event and adds it to the event mapping

Parameters:	collateralToken – Tokens used as collateral in exchange for outcome tokens oracle – Oracle contract used to resolve the event outcomeCount – Number of event outcomes
Return:	Event contract

function createScalarEvent(ERC20 collateralToken, Oracle oracle, int lowerBound, int upperBound)¶ public returns (ScalarEvent eventContract) ¶

Creates a new scalar event and adds it to the event mapping

Parameters:	collateralToken – Tokens used as collateral in exchange for outcome tokens oracle – Oracle contract used to resolve the event lowerBound – Lower bound for event outcome upperBound – Lower bound for event outcome
Return:	Event contract

Event¶

contract Event is EventData¶

Title:	Event contract - Provide basic functionality required by different event types
Author:	Stefan George - <stefan@gnosis.pm>

function buyAllOutcomes(uint collateralTokenCount)¶ public ¶

Buys equal number of tokens of all outcomes, exchanging collateral tokens and sets of outcome tokens 1:1

Parameters:	collateralTokenCount – Number of collateral tokens

function sellAllOutcomes(uint outcomeTokenCount)¶ public ¶

Sells equal number of tokens of all outcomes, exchanging collateral tokens and sets of outcome tokens 1:1

Parameters:	outcomeTokenCount – Number of outcome tokens

function setOutcome()¶ public ¶: Sets winning event outcome

function getOutcomeCount()¶ public view returns (uint8) ¶

Returns outcome count

Return:	Outcome count

function getOutcomeTokens()¶ public view returns (OutcomeToken[] memory) ¶

Returns outcome tokens array

Return:	Outcome tokens

function getOutcomeTokenDistribution(address owner)¶ public view returns (uint[] memory outcomeTokenDistribution) ¶

Returns the amount of outcome tokens held by owner

Return:	Outcome token distribution

function getEventHash()¶ public view returns (bytes32) ¶

Calculates and returns event hash

Return:	Event hash

function redeemWinnings()¶ public returns (uint) ¶

Exchanges sender’s winning outcome tokens for collateral tokens

Return:	Sender’s winnings

FutarchyOracleFactory¶

contract FutarchyOracleFactory¶

Title:	Futarchy oracle factory contract - Allows to create Futarchy oracle contracts
Author:	Stefan George - <stefan@gnosis.pm>

event FutarchyOracleCreation(address indexed creator, FutarchyOracle futarchyOracle, ERC20 collateralToken, Oracle oracle, uint8 outcomeCount, int lowerBound, int upperBound, MarketMaker marketMaker, uint24 fee, uint tradingPeriod, uint startDate)¶ ¶

EventFactory eventFactory¶

StandardMarketWithPriceLoggerFactory marketFactory¶

FutarchyOracle public futarchyOracleMasterCopy¶

constructor(FutarchyOracle _futarchyOracleMasterCopy, EventFactory _eventFactory, StandardMarketWithPriceLoggerFactory _marketFactory)¶ public ¶

Constructor sets event factory contract

Parameters:	_eventFactory – Event factory contract _marketFactory – Market factory contract

function createFutarchyOracle(ERC20 collateralToken, Oracle oracle, uint8 outcomeCount, int lowerBound, int upperBound, MarketMaker marketMaker, uint24 fee, uint tradingPeriod, uint startDate)¶ public returns (FutarchyOracle futarchyOracle) ¶

Creates a new Futarchy oracle contract

Parameters:

collateralToken – Tokens used as collateral in exchange for outcome tokens
oracle – Oracle contract used to resolve the event
outcomeCount – Number of event outcomes
lowerBound – Lower bound for event outcome
upperBound – Lower bound for event outcome
marketMaker – Market maker contract
fee – Market fee
tradingPeriod – Trading period before decision can be determined
startDate – Start date for price logging

Return:

Oracle contract

FutarchyOracle¶

contract FutarchyOracle is Proxied, Oracle, FutarchyOracleData¶

Title:	Futarchy oracle contract - Allows to create an oracle based on market behaviour
Author:	Stefan George - <stefan@gnosis.pm>

function fund(uint funding)¶ public isCreator ¶

Funds all markets with equal amount of funding

Parameters:	funding – Amount of funding

function close()¶ public isCreator ¶: Closes market for winning outcome and redeems winnings and sends all collateral tokens to creator

function setOutcome()¶ public ¶: Allows to set the oracle outcome based on the market with largest long position

function isOutcomeSet()¶ public view returns (bool) ¶

Returns if winning outcome is set

Return:	Is outcome set?

function getOutcome()¶ public view returns (int) ¶

Returns winning outcome

Return:	Outcome

LMSRMarketMaker¶

contract LMSRMarketMaker is MarketMaker¶

Title:	LMSR market maker contract - Calculates share prices based on share distribution and initial funding
Author:	Alan Lu - <alan.lu@gnosis.pm>

uint constant ONE¶

int constant EXP_LIMIT¶

function calcNetCost(Market market, int[] memory outcomeTokenAmounts)¶ public view returns (int netCost) ¶

Calculates the net cost for executing a given trade.

Parameters:	market – Market contract outcomeTokenAmounts – Amounts of outcome tokens to buy from the market. If an amount is negative, represents an amount to sell to the market.
Return:	Net cost of trade. If positive, represents amount of collateral which would be paid to the market for the trade. If negative, represents amount of collateral which would be received from the market for the trade.

function calcCost(Market market, uint8 outcomeTokenIndex, uint outcomeTokenCount)¶ public view returns (uint cost) ¶

Returns cost to buy given number of outcome tokens

Parameters:	market – Market contract outcomeTokenIndex – Index of outcome to buy outcomeTokenCount – Number of outcome tokens to buy
Return:	Cost

function calcProfit(Market market, uint8 outcomeTokenIndex, uint outcomeTokenCount)¶ public view returns (uint profit) ¶

Returns profit for selling given number of outcome tokens

Parameters:	market – Market contract outcomeTokenIndex – Index of outcome to sell outcomeTokenCount – Number of outcome tokens to sell
Return:	Profit

function calcMarginalPrice(Market market, uint8 outcomeTokenIndex)¶ public view returns (uint price) ¶

Returns marginal price of an outcome

Parameters:	market – Market contract outcomeTokenIndex – Index of outcome to determine marginal price of
Return:	Marginal price of an outcome as a fixed point number

function calcCostLevel(int logN, int[] memory netOutcomeTokensSold, uint funding, Fixed192x64Math.EstimationMode estimationMode)¶ private pure returns (int costLevel) ¶

Calculates the result of the LMSR cost function which is used to derive prices from the market state

Parameters:	logN – Logarithm of the number of outcomes netOutcomeTokensSold – Net outcome tokens sold by market funding – Initial funding for market
Return:	Cost level

function sumExpOffset(int logN, int[] memory netOutcomeTokensSold, uint funding, uint8 outcomeIndex, Fixed192x64Math.EstimationMode estimationMode)¶ private pure returns (uint sum, int offset, uint outcomeExpTerm) ¶

Calculates sum(exp(q/b - offset) for q in quantities), where offset is set so that the sum fits in 248-256 bits

Parameters:	logN – Logarithm of the number of outcomes netOutcomeTokensSold – Net outcome tokens sold by market funding – Initial funding for market outcomeIndex – Index of exponential term to extract (for use by marginal price function)
Return:	A result structure composed of the sum, the offset used, and the summand associated with the supplied index

function getNetOutcomeTokensSold(Market market)¶ private view returns (int[] memory quantities) ¶

Gets net outcome tokens sold by market. Since all sets of outcome tokens are backed by corresponding collateral tokens, the net quantity of a token sold by the market is the number of collateral tokens (which is the same as the number of outcome tokens the market created) subtracted by the quantity of that token held by the market.

Parameters:	market – Market contract
Return:	Net outcome tokens sold by market

MajorityOracleFactory¶

contract MajorityOracleFactory¶

Title:	Majority oracle factory contract - Allows to create majority oracle contracts
Author:	Stefan George - <stefan@gnosis.pm>

event MajorityOracleCreation(address indexed creator, MajorityOracle majorityOracle, Oracle[] oracles)¶ ¶

MajorityOracle public majorityOracleMasterCopy¶

constructor(MajorityOracle _majorityOracleMasterCopy)¶ public ¶

function createMajorityOracle(Oracle[] memory oracles)¶ public returns (MajorityOracle majorityOracle) ¶

Creates a new majority oracle contract

Parameters:	oracles – List of oracles taking part in the majority vote
Return:	Oracle contract

MajorityOracle¶

contract MajorityOracle is Proxied, Oracle, MajorityOracleData¶

Title:	Majority oracle contract - Allows to resolve an event based on multiple oracles with majority vote
Author:	Stefan George - <stefan@gnosis.pm>

function getStatusAndOutcome()¶ public view returns (bool outcomeSet, int outcome) ¶

Allows to registers oracles for a majority vote

Return:	Is outcome set?
Return:	Outcome

function isOutcomeSet()¶ public view returns (bool) ¶

Returns if winning outcome is set

Return:	Is outcome set?

function getOutcome()¶ public view returns (int) ¶

Returns winning outcome

Return:	Outcome

MarketMaker¶

contract MarketMaker¶

Title:	Abstract market maker contract - Functions to be implemented by market maker contracts

function calcCost(Market market, uint8 outcomeTokenIndex, uint outcomeTokenCount)¶ public view returns (uint) ¶

function calcProfit(Market market, uint8 outcomeTokenIndex, uint outcomeTokenCount)¶ public view returns (uint) ¶

function calcNetCost(Market market, int[] memory outcomeTokenAmounts)¶ public view returns (int) ¶

function calcMarginalPrice(Market market, uint8 outcomeTokenIndex)¶ public view returns (uint) ¶

Market¶

contract Market is MarketData¶

Title:	Abstract market contract - Functions to be implemented by market contracts

function fund(uint _funding)¶ public ¶

function close()¶ public ¶

function withdrawFees()¶ public returns (uint) ¶

function buy(uint8 outcomeTokenIndex, uint outcomeTokenCount, uint maxCost)¶ public returns (uint) ¶

function sell(uint8 outcomeTokenIndex, uint outcomeTokenCount, uint minProfit)¶ public returns (uint) ¶

function shortSell(uint8 outcomeTokenIndex, uint outcomeTokenCount, uint minProfit)¶ public returns (uint) ¶

function trade(int[] memory outcomeTokenAmounts, int costLimit)¶ public returns (int) ¶

function calcMarketFee(uint outcomeTokenCost)¶ public view returns (uint) ¶

Oracle¶

contract Oracle¶

Title:	Abstract oracle contract - Functions to be implemented by oracles

function isOutcomeSet()¶ public view returns (bool) ¶

function getOutcome()¶ public view returns (int) ¶

OutcomeToken¶

contract OutcomeToken is Proxied, ERC20¶

Title:	Outcome token contract - Issuing and revoking outcome tokens
Author:	Stefan George - <stefan@gnosis.pm>

event Issuance(address indexed owner, uint amount)¶ ¶

event Revocation(address indexed owner, uint amount)¶ ¶

address public eventContract¶

modifier isEventContract()¶ ¶

function issue(address _for, uint outcomeTokenCount)¶ public isEventContract ¶

Events contract issues new tokens for address. Returns success

Parameters:	_for – Address of receiver outcomeTokenCount – Number of tokens to issue

function revoke(address _for, uint outcomeTokenCount)¶ public isEventContract ¶

Events contract revokes tokens for address. Returns success

Parameters:	_for – Address of token holder outcomeTokenCount – Number of tokens to revoke

ScalarEvent¶

contract ScalarEvent is Proxied, Event, ScalarEventData¶

Title:	Scalar event contract - Scalar events resolve to a number within a range
Author:	Stefan George - <stefan@gnosis.pm>

function redeemWinnings()¶ public returns (uint winnings) ¶

Exchanges sender’s winning outcome tokens for collateral tokens

Return:	Sender’s winnings

function getEventHash()¶ public view returns (bytes32) ¶

Calculates and returns event hash

Return:	Event hash

SignedMessageOracleFactory¶

contract SignedMessageOracleFactory¶

Title:	Signed message oracle factory contract - Allows to create signed message oracle contracts
Author:	Stefan George - <stefan@gnosis.pm>

event SignedMessageOracleCreation(address indexed creator, SignedMessageOracle signedMessageOracle, address oracle)¶ ¶

SignedMessageOracle public signedMessageOracleMasterCopy¶

constructor(SignedMessageOracle _signedMessageOracleMasterCopy)¶ public ¶

function createSignedMessageOracle(bytes32 descriptionHash, uint8 v, bytes32 r, bytes32 s)¶ public returns (SignedMessageOracle signedMessageOracle) ¶

Creates a new signed message oracle contract

Parameters:	descriptionHash – Hash identifying off chain event description v – Signature parameter r – Signature parameter s – Signature parameter
Return:	Oracle contract

SignedMessageOracle¶

contract SignedMessageOracle is Proxied, Oracle, SignedMessageOracleData¶

Title:	Signed message oracle contract - Allows to set an outcome with a signed message
Author:	Stefan George - <stefan@gnosis.pm>

function replaceSigner(address newSigner, uint _nonce, uint8 v, bytes32 r, bytes32 s)¶ public isSigner ¶

Replaces signer

Parameters:	newSigner – New signer _nonce – Unique nonce to prevent replay attacks v – Signature parameter r – Signature parameter s – Signature parameter

function setOutcome(int _outcome, uint8 v, bytes32 r, bytes32 s)¶ public ¶

Sets outcome based on signed message

Parameters:	_outcome – Signed event outcome v – Signature parameter r – Signature parameter s – Signature parameter

function isOutcomeSet()¶ public view returns (bool) ¶

Returns if winning outcome

Return:	Is outcome set?

function getOutcome()¶ public view returns (int) ¶

Returns winning outcome

Return:	Outcome

StandardMarketFactory¶

contract StandardMarketFactory¶

Title:	Market factory contract - Allows to create market contracts
Author:	Stefan George - <stefan@gnosis.pm>

event StandardMarketCreation(address indexed creator, Market market, Event eventContract, MarketMaker marketMaker, uint24 fee)¶ ¶

StandardMarket public standardMarketMasterCopy¶

constructor(StandardMarket _standardMarketMasterCopy)¶ public ¶

function createMarket(Event eventContract, MarketMaker marketMaker, uint24 fee)¶ public returns (StandardMarket market) ¶

Creates a new market contract

Parameters:	eventContract – Event contract marketMaker – Market maker contract fee – Market fee
Return:	Market contract

StandardMarket¶

contract StandardMarket is Proxied, Market, StandardMarketData¶

Title:	Standard market contract - Backed implementation of standard markets
Author:	Stefan George - <stefan@gnosis.pm>

modifier isCreator()¶ ¶

modifier atStage(Stages _stage)¶ ¶

function fund(uint _funding)¶ public isCreator atStage(Stages . MarketCreated) ¶

Allows to fund the market with collateral tokens converting them into outcome tokens

Parameters:	_funding – Funding amount

function close()¶ public isCreator atStage(Stages . MarketFunded) ¶: Allows market creator to close the markets by transferring all remaining outcome tokens to the creator

function withdrawFees()¶ public isCreator returns (uint fees) ¶

Allows market creator to withdraw fees generated by trades

Return:	Fee amount

function buy(uint8 outcomeTokenIndex, uint outcomeTokenCount, uint maxCost)¶ public atStage(Stages . MarketFunded) returns (uint cost) ¶

Allows to buy outcome tokens from market maker

Parameters:	outcomeTokenIndex – Index of the outcome token to buy outcomeTokenCount – Amount of outcome tokens to buy maxCost – The maximum cost in collateral tokens to pay for outcome tokens
Return:	Cost in collateral tokens

function sell(uint8 outcomeTokenIndex, uint outcomeTokenCount, uint minProfit)¶ public atStage(Stages . MarketFunded) returns (uint profit) ¶

Allows to sell outcome tokens to market maker

Parameters:	outcomeTokenIndex – Index of the outcome token to sell outcomeTokenCount – Amount of outcome tokens to sell minProfit – The minimum profit in collateral tokens to earn for outcome tokens
Return:	Profit in collateral tokens

function shortSell(uint8 outcomeTokenIndex, uint outcomeTokenCount, uint minProfit)¶ public returns (uint cost) ¶

Buys all outcomes, then sells all shares of selected outcome which were bought, keeping shares of all other outcome tokens.

Parameters:	outcomeTokenIndex – Index of the outcome token to short sell outcomeTokenCount – Amount of outcome tokens to short sell minProfit – The minimum profit in collateral tokens to earn for short sold outcome tokens
Return:	Cost to short sell outcome in collateral tokens

function trade(int[] memory outcomeTokenAmounts, int collateralLimit)¶ public atStage(Stages . MarketFunded) returns (int netCost) ¶

Allows to trade outcome tokens and collateral with the market maker

Parameters:

outcomeTokenAmounts – Amounts of each outcome token to buy or sell. If positive, will buy this amount of outcome token from the market. If negative, will sell this amount back to the market instead.
collateralLimit – If positive, this is the limit for the amount of collateral tokens which will be sent to the market to conduct the trade. If negative, this is the minimum amount of collateral tokens which will be received from the market for the trade. If zero, there is no limit.

Return:

If positive, the amount of collateral sent to the market. If negative, the amount of collateral received from the market. If zero, no collateral was sent or received.

function tradeImpl(uint8 outcomeCount, int[] memory outcomeTokenAmounts, int collateralLimit)¶ private returns (int netCost, int outcomeTokenNetCost, uint fees) ¶

function calcMarketFee(uint outcomeTokenCost)¶ public view returns (uint) ¶

Calculates fee to be paid to market maker

Parameters:	outcomeTokenCost – Cost for buying outcome tokens
Return:	Fee for trade

StandardMarketWithPriceLoggerFactory¶

contract StandardMarketWithPriceLoggerFactory¶

Title:	Market factory contract - Allows to create market contracts
Author:	Stefan George - <stefan@gnosis.pm>

event StandardMarketWithPriceLoggerCreation(address indexed creator, Market market, Event eventContract, MarketMaker marketMaker, uint24 fee, uint startDate)¶ ¶

StandardMarketWithPriceLogger public standardMarketWithPriceLoggerMasterCopy¶

constructor(StandardMarketWithPriceLogger _standardMarketWithPriceLoggerMasterCopy)¶ public ¶

function createMarket(Event eventContract, MarketMaker marketMaker, uint24 fee, uint startDate)¶ public returns (StandardMarketWithPriceLogger market) ¶

Creates a new market contract

Parameters:	eventContract – Event contract marketMaker – Market maker contract fee – Market fee startDate – Start date for price logging
Return:	Market contract

StandardMarketWithPriceLogger¶

contract StandardMarketWithPriceLogger is StandardMarket, StandardMarketWithPriceLoggerData¶

function buy(uint8 outcomeTokenIndex, uint outcomeTokenCount, uint maxCost)¶ public returns (uint cost) ¶

Allows to buy outcome tokens from market maker

Parameters:	outcomeTokenIndex – Index of the outcome token to buy outcomeTokenCount – Amount of outcome tokens to buy maxCost – The maximum cost in collateral tokens to pay for outcome tokens
Return:	Cost in collateral tokens

function sell(uint8 outcomeTokenIndex, uint outcomeTokenCount, uint minProfit)¶ public returns (uint profit) ¶

Allows to sell outcome tokens to market maker

Parameters:	outcomeTokenIndex – Index of the outcome token to sell outcomeTokenCount – Amount of outcome tokens to sell minProfit – The minimum profit in collateral tokens to earn for outcome tokens
Return:	Profit in collateral tokens

function shortSell(uint8 outcomeTokenIndex, uint outcomeTokenCount, uint minProfit)¶ public returns (uint cost) ¶

Buys all outcomes, then sells all shares of selected outcome which were bought, keeping shares of all other outcome tokens.

Parameters:	outcomeTokenIndex – Index of the outcome token to short sell outcomeTokenCount – Amount of outcome tokens to short sell minProfit – The minimum profit in collateral tokens to earn for short sold outcome tokens
Return:	Cost to short sell outcome in collateral tokens

function trade(int[] memory outcomeTokenAmounts, int collateralLimit)¶ public returns (int netCost) ¶

Allows to trade outcome tokens with market maker

Parameters:	outcomeTokenAmounts – Amounts of outcome tokens to trade collateralLimit – The maximum cost or minimum profit in collateral tokens
Return:	Cost/profit in collateral tokens

function close()¶ public ¶: Allows market creator to close the markets by transferring all remaining outcome tokens to the creator

function getAvgPrice()¶ public view returns (uint) ¶

Calculates average price for long tokens based on price integral

Return:	Average price for long tokens over time

function logPriceBefore()¶ private ¶: Adds price integral since the last trade to the total price integral

function logPriceAfter()¶ private ¶: Updates last trade timestamp and price

UltimateOracleFactory¶

contract UltimateOracleFactory¶

Title:	Ultimate oracle factory contract - Allows to create ultimate oracle contracts
Author:	Stefan George - <stefan@gnosis.pm>

event UltimateOracleCreation(address indexed creator, UltimateOracle ultimateOracle, Oracle oracle, ERC20 collateralToken, uint8 spreadMultiplier, uint challengePeriod, uint challengeAmount, uint frontRunnerPeriod)¶ ¶

UltimateOracle public ultimateOracleMasterCopy¶

constructor(UltimateOracle _ultimateOracleMasterCopy)¶ public ¶

function createUltimateOracle(Oracle oracle, ERC20 collateralToken, uint8 spreadMultiplier, uint challengePeriod, uint challengeAmount, uint frontRunnerPeriod)¶ public returns (UltimateOracle ultimateOracle) ¶

Creates a new ultimate Oracle contract

Parameters:	oracle – Oracle address collateralToken – Collateral token address spreadMultiplier – Defines the spread as a multiple of the money bet on other outcomes challengePeriod – Time to challenge oracle outcome challengeAmount – Amount to challenge the outcome frontRunnerPeriod – Time to overbid the front-runner
Return:	Oracle contract

UltimateOracle¶

contract UltimateOracle is Proxied, Oracle, UltimateOracleData¶

Title:	Ultimate oracle contract - Allows to swap oracle result for ultimate oracle result
Author:	Stefan George - <stefan@gnosis.pm>

function setForwardedOutcome()¶ public ¶: Allows to set oracle outcome

function challengeOutcome(int _outcome)¶ public ¶

Allows to challenge the oracle outcome

Parameters:	_outcome – Outcome to bid on

function voteForOutcome(int _outcome, uint amount)¶ public ¶

Allows to challenge the oracle outcome

Parameters:	_outcome – Outcome to bid on amount – Amount to bid

function withdraw()¶ public returns (uint amount) ¶

Withdraws winnings for user

Return:	Winnings

function isChallengePeriodOver()¶ public view returns (bool) ¶

Checks if time to challenge the outcome is over

Return:	Is challenge period over?

function isFrontRunnerPeriodOver()¶ public view returns (bool) ¶

Checks if time to overbid the front runner is over

Return:	Is front runner period over?

function isChallenged()¶ public view returns (bool) ¶

Checks if outcome was challenged

Return:	Is challenged?

function isOutcomeSet()¶ public view returns (bool) ¶

Returns if winning outcome is set

Return:	Is outcome set?

function getOutcome()¶ public view returns (int) ¶

Returns winning outcome

Return:	Outcome

Indices and tables¶

Index