A changed field is a question, not an account instruction
A saved contract record can look almost identical after an update: the symbol remains familiar, the expiry looks unchanged and one numeric field has moved. It is tempting to overwrite the old multiplier everywhere. That destroys the evidence needed to understand historical records. Keep both versions, their effective dates and their saved references before calculating any difference.
This worksheet compares the quantities represented by two entered records. It does not select an order size or assert how a venue adjusted an account. The useful result is a dated, reproducible difference in units, accompanied by reasons to withhold that difference when the inputs cannot support it.
Read the product family before the digits
ASX’s Master List Manual describes a multi-purpose field. Under its index convention, the digits 1000 mean AUD 10 per index point. Equity-option and grain-futures entries instead use whole underlying shares and metric tonnes respectively. Read the corresponding underlying-unit definition as well as the product family.
The manual’s field-definition page lists 12 bytes; a later explanatory example still shows a nine-byte presentation. This tool handles an extracted numeric value of up to 12 digits and preserves its original zeros. It is not a full ASX message parser and does not resolve message-layout differences.
Sources: ASX ReferencePoint Master List Manual, version 4.0 (November 2025), pages 76 and 83.
Build a pair of versions with explicit identities
Enter one old row and one new row. Each needs a contract identifier, expiry label, family, unit, effective date, raw multiplier, recorded contract count and saved reference. Identifiers are compared exactly. Leading or trailing spaces must be removed deliberately; the tool does not trim an identifier into an accidental match.
A shared ticker does not establish that the rows describe the same legal contract. Conversely, a renamed identifier may describe an authorised successor but cannot be joined automatically here. When identity changed, preserve the relevant notice and reconcile that relationship separately. A mismatch remains a visible issue rather than becoming a fabricated conversion.
Separate an effective date from the day you collected the file
The two effective dates must be ordered and must not be later than the entered review date. These are supplied dates, not dates fetched from a venue. The tool does not infer whether the change was implemented at midnight, at a session boundary or at another instant. It compares two dated versions only.
Choose DD/MM/YYYY or ISO explicitly. In the default Australian-style example, 01/10/2026 means 1 October, not January 10. The original text and normalised ISO date are both retained in CSV. Never use the date on which a file was downloaded as an effective date unless the source actually says that.
Compare exposure in one compatible unit
For a supported family, decoded multiplier multiplied by the entered count gives the represented exposure. For the index example the unit is AUD per index point; it is not the current dollar value of the position. A current index level would be a separate input, and this worksheet deliberately does not request one.
Both versions must have the same family and expected underlying unit before a cross-version difference is available. Changing a row from index points to shares with identical digits does not preserve meaning. A mismatched unit withholds that row’s decoded result and the overall comparison; no currency conversion or unit substitution is attempted.
Work through the fictional 3-contract record
The old entry contains raw 000000001000 and a count of 3. Decoding the specified index convention gives 10 per point, so the represented exposure is 30 per point. The later fictional entry contains raw 000000002000 with the same count, giving 60 per point. Subtracting the old exposure leaves an increase of 30 per point.
These numbers illustrate a record comparison, not an actual exchange announcement. If a later confirmed record instead showed zero contracts, zero would be a known supplied count. A blank count would be unknown. Neither case authorises the tool to create fills, migrate balances or infer the cause of a change.
Preserve missing amounts and real zeros
A blank multiplier or count is retained as unknown. An explicit zero count is allowed and produces zero represented exposure when the multiplier and unit are valid. A zero multiplier is rejected because this decoder has no supported interpretation for it. It must not be used as a shortcut for an unavailable specification.
Calculations use integer arithmetic, including the two implied decimal places in the selected index convention. Original digit strings are preserved separately from decoded values. Scientific notation, grouping punctuation, signed counts and fractional contracts are outside this worksheet’s input contract and are rejected rather than rounded into something plausible.
Why matching exposure does not prove a migration
Two records can produce the same represented exposure while describing different operational events. A changed count, a changed multiplier or both might be involved. This worksheet cannot determine whether positions were adjusted automatically, closed and reopened, transferred or simply recorded incorrectly. Its result is an arithmetic relationship between the supplied records.
Keep the actual migration notice, applicable instrument scope and account evidence outside the calculated difference. If either version lacks a saved reference, the overall comparison is withheld. A plausible number is useful for asking a specific question; it is not a substitute for the evidence that answers it.
Export an audit trail without rewriting the originals
The CSV includes the original fields, ISO dates, decoded values, unit labels and issue codes. The visible table uses plain-language issue descriptions. Spreadsheet-sensitive strings are quoted and prefixed when needed to reduce formula execution on import. Review your spreadsheet’s import settings and keep the source files as separate evidence.
The tool runs locally after loading. No specification endpoint or account service is queried, and no record is saved automatically. Editing any field clears the previous export so an old CSV cannot masquerade as a result for new inputs. The optional site offer follows the resource; access to the calculation does not require joining a channel.
Worked examples
Example 1
The fictional old raw multiplier 000000001000 decodes to AUD 10 per index point; 3 contracts represent AUD 30 per point. The fictional new value 000000002000 decodes to AUD 20 per point; the same 3 contracts represent AUD 60 per point. The entered exposure change is AUD 30 per point. This is not a claim that an ASX contract changed, that an account was migrated or that a trade should be placed.
Inspect example inputs
{
"date_format": "DMY",
"as_of_date": "21/10/2026",
"rows": "version|contract|expiry|kind|unit|effective_date|raw_multiplier|contracts|reference\nold|DEMO-INDEX|DEC-2026|index_futures|index_points|01/10/2026|000000001000|3|DEMO saved old specification\nnew|DEMO-INDEX|DEC-2026|index_futures|index_points|20/10/2026|000000002000|3|DEMO saved new specification"
}Questions about the method
Does a matching symbol prove both versions belong together?
No. Exact text equality is a necessary input check here, not independent proof of contract continuity.
Does the result tell me how many new contracts to hold?
No. It compares recorded counts and multipliers; it does not calculate or recommend a replacement order.
Why is a future effective date rejected?
This worksheet is for comparing supplied past versions. A scheduled change needs its own clearly labelled future-event record.
Primary sources and scope
- ASX ReferencePoint Master List Manual, version 4.0 (November 2025), pages 76 and 83Checked 2026-10-21. The field represents different quantities by product family. Index values encode AUD per point with two implied decimals; equity-option values are shares and grain-futures values are tonnes. The current field definition lists 12 bytes while an explanatory example elsewhere uses nine; this worksheet accepts extracted digit strings, not whole fixed-width messages.
Examples explain a method. They do not predict prices or establish where a trading service is available. Check the named source before relying on future schedules.