Where Does Your Money Actually Sit?

Polymarket's help centre puts the collateral claim like this:

“every pair of event outcomes (i.e. each pair of ‘YES’ + ‘NO’ shares) is fully collateralized by $1.00 USDC” help.polymarket.com, What is Polymarket, read 11 August 2026

Kalshi's event contracts work on the same principle: every side is paid for in advance, and a resolved market pays out of collateral posted before the trade existed.

That rules out a real failure mode. Neither venue can be short of money because a position moved against somebody who could not pay. There is no leverage on an ordinary event contract, so no margin call and no forced liquidations.

What it does not rule out is everything else. Notice what the sentence is a claim about. It is a claim about the contract: the pot is full. It says nothing about who holds the pot, whether they may spend it, what happens to it in a bankruptcy, or whether anybody will make you whole if it goes missing. Three claims get compressed into the word “safe”, and only one is insurance.

Why neither SIPC nor the FDIC applies

SIPC is the body that steps in when a stockbroker fails, and it is explicit about the boundary:

“SIPC does not protect commodity futures contracts (unless held in a special portfolio margining account)” sipc.org, What SIPC Protects, read 11 August 2026

The same page excludes “investment contracts… that are not registered with the U.S. Securities and Exchange Commission”. Event contracts on a CFTC-designated exchange sit on the futures side of the fence, not inside a SIPC-member brokerage. Wrong body.

The FDIC is the wrong body for a subtler reason. Its insurance covers bank deposits against the failure of the bank, and its own list of products it does not insure names “Stock Investments, Bond Investments, Mutual Funds, Crypto Assets… Annuities, Municipal Securities” among others. So when a venue says it keeps customer cash at FDIC-insured banks, note what is insured and against what: the cover protects that deposit from the bank going under. It does not protect you from the venue going under, and it does not attach to an open position at all. “Held at an FDIC-insured bank” and “your balance is insured” are different sentences, and only the first is usually the one being said.

And collateralisation is no longer universal inside one venue

Kalshi now lists margined perpetual futures alongside its event contracts, and its documentation for that product says:

“As with any margined futures, losses in black swan scenarios can exceed posted margin.” help.kalshi.com, How Margin Works, read 11 August 2026

Same platform, same login, opposite risk profile. On an event contract your maximum loss is the money you put in. On a margined perpetual it is not.

Polymarket's answer to the custody question is that there is no custody:

“Polymarket is non-custodial, so you're in control of your funds” … “we never take possession of your USDC” help.polymarket.com, Is My Money Safe?, read 11 August 2026

Mechanically: your collateral is USDC, a dollar-referenced token issued by a private company, held at an address on Polygon, a blockchain separate from Ethereum. Your positions are token balances at that address, and moving any of it needs a signature from the key that controls it. Polymarket runs the interface, the matching and the resolution. It does not hold the balance. That cuts both ways.

“Non-custodial” is a property of the architecture. Whether it is a property of your account depends on how your key is stored, which is not obvious from the screen. The only test that matters: who can produce a valid signature without your involvement?

• You hold the key. A wallet you set up, with a recovery phrase you control. Nobody can move your funds, and nobody can help you if you lose it.
• Somebody else holds it for you. An embedded or social-login wallet, a custodial exchange account, or a bot you granted signing rights to. It reintroduces the counterparty you were told did not exist.

Polymarket states that “You can export your private key at any time, ensuring sole access to your funds”, so the test is one you can run. The same page states the cost of being your own custodian:

“Losing your private key or passwords can result in losing access to your funds.” help.polymarket.com, Is My Money Safe?, read 11 August 2026

There is no recovery process behind that sentence. Treat the recovery phrase as the asset, because here it is.

Whether your money can move at all

Polymarket publishes a geoblock endpoint. Read on 5 August 2026 and checked again on 11 August 2026, it lists the United States as close-only on both the frontend and the API: existing positions may be closed and new ones may not be opened. The same status applies to the United Kingdom, France, Germany, Italy, Poland, Belgium, Slovakia, Australia, Singapore and four Canadian provinces (British Columbia, Ontario, Alberta and Quebec), among others. If you are in one of those places, the answer to this page's title is: in a position you can exit and cannot add to.

Polymarket US is a different thing with a similar name

QCX LLC, operating under the assumed name Polymarket US, appears on the CFTC's filings register as a designated contract market, dated 9 July 2025, with the remark that “QCX LLC is now operating under the assumed name of Polymarket US”. Its clearing house, QC Clearing LLC trading as Polymarket Clearing, is a registered derivatives clearing organisation. That venue has segregated customer funds and sits structurally closer to Kalshi than to polymarket.com, so look up the entity, not the logo.

The acquisition that brought that entity under the Polymarket name is widely reported with a specific price attached. We have not found that figure in any filing, order or other primary document, so it does not appear here. The amount is not independently verified. The registrations above are.

Counterparty risk is not only a question about money. It is a question about who you would have to find.

Polymarket's Panamanian corporate filings give a headquarters address on the 21st floor of the Oceania Business Plaza in Panama City. NPR went to it and published what it found on 5 May 2026: a law office, a lobby opening onto a room with about a dozen unoccupied computer stations, no sign of Polymarket and no sign of Adventure One QSS Inc, the entity Polymarket does business as in Panama. A worker there had not heard of either name. NPR also reported that at least 15 other cryptocurrency companies use the same office as their registered headquarters.

Be careful about what that does and does not establish. Registering at a law firm's address is ordinary corporate practice in many jurisdictions and is not evidence of wrongdoing. What the finding establishes is narrower and still material: the address in the public record is not a place where you would find anybody responsible for your money.

That matters because an address is what a dispute needs. Segregation is enforceable because there is a named registrant, a regulator, and a court that will hear the case. When the registered address resolves to a shared law office in a jurisdiction you have no relationship with, “who do I bring a claim against, and where” has no cheap answer. That is not a claim that your funds are at risk. It is a claim that your recourse is thin, and recourse is most of what you are buying when you accept a counterparty.

Kalshi's answer is dull, and dull is the point: named US entities, a named regulator, a public filings register, and a clearing house whose order of registration is published. That is not a verdict on which venue prices better. It is a difference in where you would be standing if something went wrong.