A "contract" on PredictIt refers to every possible answer to the question posed in a market.

Some markets end on a specific “end date” displayed on the market page. Unless otherwise specified in the Rules, these markets will be considered closed at midnight Eastern Time on the end date. Other markets have no specified end date.

PredictIt reserves the right to close markets at any time, including earlier than a specified end date if, in our judgment, the conditions to decide the outcome have been met. See the Rules that govern each market for detailed information on how we determine which side has won.

We try to offer contracts on the most likely outcomes in a market but we don’t try to be comprehensive. If we don’t mention the candidate for office that you think might win, try buying No in all the other candidates or post your suggestion in our user Forum.

Absolutely! Please post your suggestion on our user Forum under “Market Suggestions”.

Prices should normally add up to $1 (100% probability) since there will always be one and only one winning outcome in any market. But since the price assigned to each potential outcome is a reflection only of the most recent trade in that contract, the sum of all prices can be higher or lower than $1, especially if there has been rapid change in any one of them.

A lot. A pollster estimates the percentage of the vote a candidate might win on election day. Players on PredictIt estimate the chance that a candidate will win the election. For example, a candidate in a two-person contest might be leading her opponent 60% to 40% in the polls. Candidates who are leading by a margin this large almost always go on to win. Consequently, PredictIt may show a probability for the leading candidate of 95% or higher.

The price listed after the latest price represents the change in price since midnight Eastern Time. Prices in green, with an up arrow, represent a rise in price. Red indicates a fall in price.

The latest price is determined by the most recent trade made between two players. Very often, other players will want to buy or sell shares at a price slightly better for them, usually a cent or two, than the most recent trade.

Good question! Knowing exactly when to buy and to sell is the essence of trading, and it’s as much art as science. Generally speaking, it makes sense to look for markets that you think are mis-pricing the chance of an event taking place or that are logically inconsistent (“inefficient”), i.e. the sum of all predictions is significantly above or below 100%.

Whatever you do, just make sure to manage your risk so that if you turn out to be wrong about a few things, you don’t end up losing more than you can afford.

If your prediction is right, we’ll redeem your shares for $1 each, less our fee on the profit you have earned.

If you’re convinced you’re right about an outcome in a market, you’ll want to wait until the closing date to maximize your winnings. But nothing is certain and doing well at PredictIt will generally involve watching prices carefully and selling your shares at a profit at the right time, rather than waiting until the end.

You certainly can. In fact, PredictIt depends on players offering prices and seeing if another player will match them. If you don’t see a price you like, name the price and quantity you’re looking for and we’ll register an Offer for other players to match.

We give you the most recent information on the Buy or Sell screen, but it’s possible that another trader will have beaten you to the punch and bought the shares you were looking for before you hit “Submit”. Trades are first come, first served.

PredictIt operates under no-action relief from the Division of Market Oversight of the Commodity Futures Trading Commission. An $850 limit on investment by an individual participant in any contract is a condition of this relief.

We calculate the $850 limit per contract according to the aggregate price you paid for the shares you own in a particular contract. Subsequent changes in the market value of your shares do not change this calculation. If you sell some or all of your shares, whether at a profit or at a loss, the initial cost of these shares will no longer be counted towards your limit.

PredictIt operates under no-action relief from the Division of Market Oversight of the Commodity Futures Trading Commission. A limit of 5000 traders holding shares in any one contract is a condition of this relief. You will be able to buy shares in a contract that has reached the 5000 trader limit only when another trader sells all of his or her shares, thereby exiting the contract.

You can’t own shares on both the Yes and the No side simultaneously. Sell your stake in one side if you decide you want to buy on the other.

When, in PredictIt’s judgment, the conditions for settlement of a contract have been met, or when a prescribed end date has passed, PredictIt will suspend trading activity pending confirmation of the circumstances and contract rules. This review period can take up to 48 hours, but is often much shorter. In rare cases, where the circumstances are ambiguous, it can take longer.

Once the review is complete, the contract is formally closed. PredictIt redeems each winning share for $1. All other shares have no value. A calculation of the amount credited to your account will appear in History.

You can cancel an offer on the Ownership page, which is available both via My Shares and in an Ownership tab on the individual contract trading page.

You must have the necessary funds available to cover your offers in any individual contract. If you try to place an offer in excess of your available funds, PredictIt will reduce your offer to the point at which you are able to pay. You are also not able to make an offer that, if matched, would place you over the $850 limit in any contract.

More than likely, your open offers have been reduced because your available balance declined, either because you withdrew funds from your account or made other purchases. Remember that you have to have funds available to match your open offers in any individual contract. You were able to cover your offer at the time you made it, but couldn’t do so once your balance changed.

Yes. You can make multiple offers across markets and contracts so long as your available balance is sufficient to cover your open offers in any individual contract. Of course, once that offer is matched and your available funds decline, your other offers are likely to be reduced.

PredictIt deducts only the amount necessary to cover a trader’s potential losses (“risk”) in both single-contract and multiple-contract markets. In a single contract market, the calculation of risk is very simple: it equals the amount you paid for your shares because if your prediction is wrong, you will lose your investment in those shares. In markets with multiple contracts, the calculation of risk is more complicated, but the principle is the same. There is no reason for us to deduct more from a trader than he or she could possibly lose.

PredictIt calculates your profit or loss in the market as a whole for every possible outcome. Your least favorable scenario (greatest loss or smallest profit) represents your “market risk”. These calculations of risk are readily available on the site.

We strive to keep things simple but, in this case, doing so would distort the market. Not debiting by risk would make it artificially difficult for traders to buy ‘No’ shares in multiple contracts in the same market. The result could be aggregate probabilities in many multiple-contract markets of over 100%. (Remember, since there can only be one winner, the sum of all probabilities should approximate 100%, or $1 in price.) For researchers, these kinds of valuations would diminish the usefulness of PredictIt’s data. For traders, they would impose unnecessary burdens on those wishing to buy both “Yes” shares (whose prices would be too high) or “No” shares (which would be artificially costly). Besides, there’s no reason for us to debit a trader’s account more than is necessary to cover the cost of a share.

A full description of buying and selling shares in multiple-contract markets is available on How It Works.

Whenever you buy or sell shares in a multiple-contract market, PredictIt credits or debits your account according to your change in risk. If selling certain shares causes your overall risk to increase, you will have to have sufficient funds to cover the additional risk.

You don’t actually “pay” for all your shares in multiple-contract markets. Indeed, it is often possible to acquire shares in several contracts in the same market and have funds credited to your account in the process. When you hold shares in contracts within the same market you are, in effect, hedging your position, ensuring that your losses in one contract will be offset by gains in the others. When you sell off your position in those parallel contracts – to pocket a gain on those shares, for example – you are exposing yourself to greater risk if your position in the remaining contract(s) doesn’t pan out. Since you didn’t “pay” for those shares in the first place, you have to do so at the time of the new transaction.

It has no effect. You can invest only $850 at most in any individual contract even if your market risk is lower.

When a market closes, PredictIt redeems all of the existing shares in that market. If your prediction comes true, you functionally sell your shares back to us for $1. Otherwise, their value is zero. The closing price and the calculation of your profit and our fee appear in History.

Contracts in multiple-option markets are closed sequentially, with the contract that resolved to “Yes” always closed last (at the top of the list for that market in History). As we close each contract, we recalculate your market risk based on your holdings in contracts that remain to be closed. Your overall credit in the market will be the sum of your credit in each individual contract.

Prediction markets work best when players have some stake, however small, in the outcome. With play money, many players take risks they wouldn’t otherwise take or don’t attend to their holdings as carefully. Such markets may therefore have less research value than real money ones. Besides, we think real money is fun too.

We are required to verify your identity and that you are over 18 as a condition of our regulatory approval by the CFTC.

We collect your date of birth as part of the identity verification process to insure players are not minors, to reduce fraud and duplicate accounts, and to protect the integrity of the market for the benefit of all players.

Any time you sell a shares for a higher price than you paid, we charge a fee of 10% of your profit. There is no fee if you sell your shares at the same price that you paid or at a lower price. There is also no charge to open an account with us or to deposit funds.

PredictIt charges a 5% fee to process withdrawals. For traders outside the United States, we also pass along a $40 wire fee charged by our bank. Traders receiving wire transfers are also responsible for any fees that may be charged by their own banks.

The following applies only to traders resident in the United States.

Pursuant to IRS regulations, PredictIt is required to issue Form 1099 to any trader who has a net profit of $600 or more in any calendar year. For IRS purposes, net profit is calculated as follows:

Net Profit = Gross Profits – Losses – Trading Fees – Withdrawal Fees.

The 5% withdrawal fee is included in the calculation whether or not the funds in question have actually been withdrawn from the account.

For example, a trader who had gained $1000 on the sale of some shares, lost $200 on the sale of other shares, and had paid $100 in fees on her profitable trades would have $700 remaining before the 5% withdrawal fee. Net profits for tax purposes would be:

$1000 - $200 - $100 - $35 = $665

Yes, PredictIt makes live market data publicly available via an API (Application Program Interface). The latest trade price and the best offers to buy and sell shares are available for any active market via the API. Data is updated every sixty seconds.

If you wish to receive data for all markets in a category (ex. U.S. Elections), the format for the API URL is:

https://www.predictit.org/api/marketdata/category/[id]

where [id] refers to the category ID for the Category.

Example:

U.S. Elections

https://www.predictit.org/api/marketdata/category/6

If you wish to receive data for all markets in a sub-category (ex. U.S. Elections/Electoral College), the format for the API URL is:

https://www.predictit.org/api/marketdata/group/[id]

where [id] refers to the group ID for the sub-category.

Example:

U.S. Elections / Electoral College

https://www.predictit.org/api/marketdata/group/75

You can find the ID numbers for categories and sub-categories (groups) in their respective URLs.

The format for the API URL for any single market or contract is:

https://www.predictit.org/api/marketdata/ticker/[tickersymbol]

where [tickersymbol] refers to the ticker symbol for either an individual contract or a market as a whole.

Here are two examples:

Market: Who will win the 2016 U.S. presidential election?

https://www.predictit.org/api/marketdata/ticker/USPREZ16

Contract: Will Hillary Clinton win the 2016 U.S. presidential election?

https://www.predictit.org/api/marketdata/ticker/CLINTON.USPREZ16

Finally, the format for the API URL to return data for all active markets is:

To change the return type for any of the above, add one of the following to the request header.

Accept: application/xml

Accept: application/json

When trading volume on a particular market is especially heavy, PredictIt posts a notice at the top of the market and contract pages advising you to expect longer than normal processing times. If heavy volume prevents us from processing your offer in a timely manner, you will receive notification that your request is “in process”. Offers are processed in the order in which they are received. Do not resubmit offers that are already in process.

You can see your offers “in process” in the ownership view. “In process” offers can be cancelled before processing in the same manner as open offers.

You can buy or sell shares, deposit or withdraw funds on PredictIt at any time with the exception of 0400 to 0430 Eastern U.S. Time (New York). Trading is suspended during this half-hour period to allow us to perform routine maintenance. You can still log into your account, view your holdings and cancel offers during the daily maintenance period. PredictIt reserves the right to suspend trading in any market at other times at its sole discretion.