Enforced margin as the real futures trade guarantee

Settlement is not a profit promise

A futures exchange clearing-guarantee covers settlement at the contracted entry and exit prices rather than any profit outcome for the speculator. The assurance is that a cleared trade settles at those contracted prices, not that the speculative position will be profitable.

A profitable foreign-exchange trade still depends on the opposing party paying, so counterparty-risk remains even when historical defaults have been uncommon.

The deposit must already be posted

Exchange rules require a specified risk-based deposit before a trader may buy or sell a futures contract or sell an option short. Establishing a position on a US futures exchange requires that this futures-margin already be on deposit.

If deposits are not large enough to cover potential position drawdowns, exchanges and brokerage firms absorb the risk that a losing speculator abandons the account.

Enforced margin and the liability stack

In the late 2000s, a large housing market allowed purchases with little or no down payment, and some buyers later defaulted, leaving lenders with the unsold liability.

Futures exchanges, unlike that housing episode, actively enforce margin rules in an attempt to support liquidity and a more stable marketplace. US futures exchanges sit at the top of a liability-stack so that default risk from retail clients is borne first by parties closer to the trade.