Write the price pair and the chosen difference
A label such as premium or basis is incomplete without its formula. Preserve the instrument identities, observation instants, quote unit and the direction of the difference. Futures minus spot and spot minus futures assign different signs to the same entered pair.
Market-data schemas can name separate absolute, rate and annualised fields without establishing one universal formula for every publication. Read the relevant definition rather than treating similar labels from two sources as interchangeable.
Compare two fictional denominators explicitly
Enter a spot reference of 100 quote units and a futures reference of 105 in the same unit and teaching snapshot. Futures minus spot is 5 quote units. Dividing that difference by spot gives 5/100=5%. Dividing it by the futures reference gives 5/105, about 4.7619%.
The second percentage is not an arithmetic correction of the first. It uses another denominator. If a source supplies only a percentage and no definition, the price comparison cannot be reconstructed uniquely from the label alone.
| Teaching statistic | Formula for S100,F105 | Result |
|---|---|---|
| Absolute difference, F−S | 105 − 100 | 5 quote units |
| Difference over spot | 5 / 100 | 5% |
| Difference over futures | 5 / 105 | About 4.7619% |
| Reverse difference, S−F | 100 − 105 | −5 quote units |
An annualised figure needs an additional declared model
A dated maturity, elapsed duration and day-count convention can change an annualised label. An interval rate cannot become an annual figure merely by renaming its column. A perpetual product also does not acquire a supplied expiry because another row in the table has one.
Keep the original non-annualised measure beside any modelled scaling. A precise extrapolation is not evidence of a future realised return. Missing duration or a missing formula should remain unresolved rather than being inferred from an attractive displayed percentage.
Preserve quote comparability and the Singapore reporting layer
The fictional prices share a quote unit and observation assumption. A USD price and an SGD display need conversion evidence before they can form the same difference. Likewise, a later spot snapshot is not automatically the reference used for an earlier futures observation.
Bid, ask, last trade and a separate reference index are different price definitions. Preserve the supplied definition even when the numerical values happen to match. Neither a basis number nor a matching quote notional establishes equivalent risk or an executable spread.
Give every reported number its own definition
A useful comparison retains the original prices and can report 5 quote units,5% over spot and about 4.7619% over futures with their respective formulas. It should not call one source wrong until the definitions and inputs are comparable.
All values here are invented. The article authenticates no quote, funding payment or profitable carry opportunity and recommends no trade. It complements a premium worksheet by explaining a source-definition difference before the optional offer link.
The optional link below leads to this site's separate crypto signals and Telegram updates offer. The record method is usable without that offer. It does not independently verify the offer, establish country eligibility or turn the teaching example into an actual transaction.
Primary sources and scope
- Binance Developer Docs: COIN-M market-data schema
Market-data schemas distinguish basis, basis-rate and annualised fields. This article does not infer a universal formula or use live quotes. Checked 2026-10-21. - Python documentation: rational arithmetic
Exact rational arithmetic independently checks the invented numerical examples; no actual fee, signal or trade is authenticated. Checked 2026-10-21.