Interactive Brokers is worth a look if you already hold an IBKR account and want event contracts next to your investments, particularly for economic and climate questions. Its advantage is the account around the trade. Opening a brokerage relationship just to place one casual prediction is a bigger step than a one-cent fee headline suggests.
The cost also depends on which exchange supplies the contract, so one platform label is not enough to compare.
Account, venues and eligibility
IBKR’s event contracts page says its prediction markets platform gives access to three exchanges: Kalshi, CME Group and ForecastEx. Its disclosures say event contracts are available only to eligible clients aged 21 or older, and that ForecastEx contracts on US election results are limited to eligible US residents. Having an account does not mean you can trade every contract.
ForecastEx is an affiliate of Interactive Brokers, and IBKR’s disclosure says the displayed prices reflect market sentiment from ForecastEx and other registered exchanges. A 70-cent price is a market price, not a broker telling you there is a 70 percent chance.
Fees depend on the venue
IBKR’s published US schedule lists, per contract:
| Venue | IBKR commission | Exchange fee | Total |
|---|---|---|---|
| ForecastEx | $0.00 | $0.01 | $0.01 |
| Kalshi | $0.01 | $0.01 | $0.02 |
| CME Group | $0.01 | $0.01 | $0.02 |
IBKR says clients introduced by another broker or managed by an advisor may pay more, and that rates can change.
Here is the arithmetic for 100 ForecastEx contracts at a hypothetical 60 cents. The position costs $60 and the opening exchange fee adds $1, for $61. A $100 settlement leaves $39 above that outlay, ignoring other costs. The same trade under the $0.02 schedule would cost $62.
That isolates the fees only. A price two cents worse costs more than a one-cent fee saving, so compare the same outcome, quantity and settlement wording before calling either venue cheaper.
ForecastEx positions close by taking the other side
IBKR’s ForecastTrader lesson says winners receive a standard $1.00 per contract and that positions can be exited at any time by taking the opposing side. In practice, closing a Yes position means buying the matching No, which offsets it.
A hypothetical example: you buy Yes at 60 cents, then later buy the matching No at 30 cents. Together they cost 90 cents against a combined $1 value, before fees. Confirm the order preview before you submit, and do not treat this as a closing instruction for Kalshi or CME contracts reached through IBKR.
The incentive coupon
ForecastEx contracts pay an interest-like incentive coupon, based on the closing market value of the position, accruing daily and paid monthly. IBKR’s prediction markets page listed 3.38% APY on November 2, 2026, and says the rate can change. On an unchanged $100 position for 30 days, that comes to about 28 cents on a simple 365-day basis. It is a payment attached to a risky position, not savings protection, and it will not rescue a badly priced short-term trade.
Who it suits
An eligible existing IBKR customer interested in economic releases or climate indicators has a concrete reason to explore ForecastTrader. For anyone who would open a new account for a single event, the paperwork may outweigh a small fee saving.
This review rests on IBKR’s public documentation, checked November 2, 2026. We did not fund an account, place an offset trade or test a withdrawal.
See also our prediction market hub.
