Funding cash flows: reconcile settlements separately from trade profit

A funding rate is not a cash receipt

We keep observed rates, estimated charges, and settled cash flows in separate records throughout this example.

An autonomous perpetual-market agent may observe an upcoming funding rate and estimate a charge. The estimate is an input to its decision. A settled account entry is evidence of an actual cash movement. Combining the two as if both were realized can double-count costs and misstate performance.

Bybit's funding explanation describes rates that change before the funding timestamp and a funding fee calculated from position value at settlement. It also documents that settlement frequency and limits can change. A fixed eight-hour assumption is therefore insufficient as a universal accounting rule.

An illustrative signed ledger

Assume a hypothetical linear position with settlement value 10,000 quote units. At the first settlement, the applicable rate is positive 0.01%, and the account's long position pays 1 quote unit under the example's convention. Record a cash flow of -1.

At a second settlement, the position value is 8,000 and the applicable rate is negative 0.02%. Under the same illustrative convention, the long receives 1.6. Record +1.6. Net funding cash flow is +0.6.

Suppose trading executions separately generate gross realized profit of 20 and trading fees total 3. If these are the only cash effects, the combined realized result is 20 - 3 + 0.6 = 17.6. No funding estimate should be added again. These values and signs are illustrative teaching inputs.

Keep three records separate

Store the observed prospective rate with its observation time and expected settlement time. Store an estimate with the position value assumption, product formula, and sign convention. Store the settled ledger entry with its actual amount, currency, timestamp, and venue identity.

When settlement arrives, reconcile the estimate against the receipt. Differences can arise from a changed rate, changed position, changed mark value, contract formula, or timing boundary. Preserve the difference rather than rewriting the earlier estimate. The estimate describes what the agent knew before acting; the receipt describes what happened.

A position held briefly across settlement may have a different funding experience from one held for most of the interval but closed beforehand. Apply the venue's eligibility and timing rules rather than prorating elapsed time unless the product explicitly does so.

Test funding independently of prediction

An offline fixture can contain two settlement entries, a duplicated delivery, and an earlier estimate that differs from the first receipt. Assert signed totals by currency and verify that only settled entries enter the realized cash ledger. The estimate remains in the decision trace.

Inverse contracts can settle in a base asset and use a different position-value formula. Other venues can have different schedules or charging conventions. Reporting conversions require their own timestamped rate, and the interval's actual rate belongs in the calculation alongside any displayed annualized figure.

Funding is one component of decision economics. Price prediction skill and portfolio choice require evidence beyond a positive funding receipt. Separating the ledger lets researchers ask whether an agent accounted for the cash mechanics accurately before testing those broader claims.

Fit the receipt into the full trace

Our execution and settlement framework connects these mechanics to recorded outcomes. The operating-layer controls paper explains why the machinery around an agent deserves its own evaluation.