Comparing selected stock listing histories

1. Build an exact roster

The US stock catalogue loads automatically; use Pin for comparison on any additional rows you want. The roster identifies exact rows and their catalogue capture, not just a name, ticker or CIK. One CIK can have several share classes or listings; none is automatically merged.

Pin two to six rows. Reorder them with the arrow controls, remove individual choices or clear the roster. Search and filtering do not load prices for the whole catalogue. Changing the pinned selection reads only its at-most-six members. A catalogue selection does not prove that every listing is available.

2. Choose a history range

Choose 1mo, 3mo, 6mo, 1y or 5y with daily interval 1d. The selected roster loads automatically, with at most two reads at once. Review every input’s native symbol, name, venue, instrument type, currency, actually returned range and capture. Availability of all five ranges for every listing is not assumed.

The SEC candidate and native Yahoo listing remain separate source records. Matching a name or ticker alone does not prove CIK issuer or share-class identity. Failure of one member neither shrinks the roster nor substitutes a similar symbol; the previous dated comparison remains retained.

3. Read the whole validated comparison

The whole comparison appears after every native identity, currency and range is checked. A failed member is never silently omitted. Changing the selection or range cancels the old request and reads the new one; Refresh comparison explicitly repeats the read.

Every member must have exactly the same native currency token, including letter case. USD, GBP, GBp and GBX are neither interchangeable nor converted. A dimensionless base-100 curve does not permit mixing currencies.

4. Select a local time window

Within the captured input, enter From and Through inclusive; both dates are included by the UTC date of the original timestamp. Apply time window creates the new applied view. Whole captured period removes the local restriction. Window changes download nothing and do not change the history range requested from the provider.

A window may contain gaps or too few common points; missing days are not invented and prior prices are not substituted. A new comparison basis is sought inside the window. Every original point, including those outside the window, remains in the whole table, evidence and export with its exclusion reason.

5. Read common points and gaps

The base of 100 is the first shared completed exact source timestamp inside the applied time window at which every member has a positive Close. At least two common usable points in the window are required. Each curve uses original Close divided by that member’s Close at the shared basis; the basis is not moved to a different day for each stock.

The calculation 100 × Close / own basis uses an exact fraction and one HALF_EVEN rounding to at most 24 decimal places. The basis is 100; a genuine zero Close after the basis remains zero rather than a gap.

Exact native timestamps are joined, not nearby trades or merely matching UTC dates. An absent timestamp, null Close, current session and pre-basis point remain distinct; none is replaced by zero or a previous price. The table offers all, common and excluded points, pagination and original point evidence.

This compares the original Close series, not total return with dividends, fees or taxes. Separate Adj Close does not replace the input. A daily timestamp is not a confirmed closing trade time; a current quote has its own timestamp. This view derives no volume sum, FX, correlation, alpha or portfolio.

6. Inspect evidence and export the whole comparison

The chart, complete table and point detail share one applied query, result and manifest. In evidence, inspect every native identity, original Close and basis, exact timestamps, SHA-256 and individual source captures. Cache describes application reuse, not current market validity.

Whole JSON and readable CSV retain every original input, basis, common and excluded point, including all points outside the time window, and its reasons. Neither the current page nor selected detail narrows the file. Before download, every same retained original is checked through the current local gate; a missing or expired member blocks the whole export rather than substituting a newer price. A new set requires an explicit read.

This local analytical file is not a named account configuration, canonical Snapshot, ValuePassport or public share. Catalogue coverage is not a count of histories already acquired.