What this methodology covers
A first-day price rise, a return earned after buying in the market and an improvement in the business are different outcomes. The planned tracker will show them separately. This page defines ipo.zone's measurement conventions, not exchange rules or a forecast of how an IPO should perform.
Implementation status. The live performance module is not yet available. These are the definitions for its build, not a claim that the current tracker already calculates these measures. Not investment advice.
Use the first-day return calculator for an offer-to-close illustration. Its optional day-30 input is a manual scenario: the user supplies the date and benchmark levels. It does not enforce the tracker conventions below or verify sources.
Dates, units and return bases
Day 1 is the venue-confirmed first trading session for the listed share, not an expected admission date. Day 30, day 90 and day 180 mean the corresponding numbered sessions on that venue's calendar, counting day 1. These are product labels, not calendar-day anniversaries. Weekends and venue holidays do not count; a suspension does not stop the session clock. We show each actual endpoint date and never substitute the latest available price for a missing endpoint.
Offer-to-close measures start at the final offer price. Aftermarket measures start at the official first-day close and therefore exclude the offer-to-first-close move. An investor buying at that close has a different starting point from an investor receiving an IPO allocation.
Calculations use decimal returns internally: a displayed percentage is the decimal result multiplied by 100. A difference between two percentage returns is expressed in percentage points, not as a percentage improvement. We round only the displayed result.
Our headline offer-to-close measure is a price return, excluding cash dividends, fees, taxes and financing costs. Prices must be on the same currency and share-unit basis, with verified adjustments for splits and other capital changes. A zero closing price is accepted only if officially confirmed; it is never a missing-value code.
Aftermarket CAR and BHAR are separately labelled price return or gross total return. A gross total-return series reinvests cash distributions before investor-specific tax. We require the same return basis for the share and the benchmark. We do not compare a dividend-inclusive share return with a price-only index, splice incompatible series or silently replace a missing total-return calculation with a price return.
Initial return: offer price to first-day close
Initial return measures the change from the final offer price to the official first-day closing price, not the opening auction price or an intraday high.
Initial return = first-day comparable closing price / final offer price - 1
The offer price must be positive and both prices must refer to the same share class, currency and economic share unit. For a direct listing without an offer price, the initial return is no official data — not applicable. A reference price is not silently relabelled as an offer price. A close-to-close aftermarket series may still be possible.
This measure describes an allocation-price outcome before costs. It does not assume every investor could obtain an allocation at that price.
Market-adjusted initial return
We subtract the chosen market benchmark's price return from the initial return:
Benchmark first-session return = benchmark close on day 1 / benchmark close on the preceding venue session - 1
Market-adjusted initial return = initial return - benchmark first-session return
The benchmark interval is explicitly preceding-session close to first-day close. An offer may have been priced earlier, so this is a first-session market proxy, not a precisely synchronized offer-pricing-to-close investment. The tracker will disclose this limitation instead of suggesting exact timing alignment.
This simple adjustment does not estimate market sensitivity, control for sector or size, or establish that the listing caused an abnormal return.
CAR: adding daily differences
Cumulative abnormal return (CAR) in this tracker means the sum of daily market-adjusted returns. Here, "abnormal" means relative to the selected benchmark, not a fitted statistical model.
Share daily return = comparable share level today / comparable share level on the preceding session - 1
Benchmark daily return = comparable benchmark level today / comparable benchmark level on the preceding session - 1
Daily abnormal return = share daily return - benchmark daily return
CAR = sum of daily abnormal returns over the stated window
Our default aftermarket window begins at the day-1 close. For a day-30 endpoint, daily intervals run from day 1 to day 2 through day 29 to day 30. The initial return is not included. A total-return calculation uses verified gross total-return levels in place of price levels on both sides.
CAR needs every interval in the stated window. A missing session observation invalidates that full-window CAR; we do not add the available days and label the result complete. CAR is an additive return spread, not the compounded return on an investment.
BHAR: comparing buy-and-hold wealth
Buy-and-hold abnormal return (BHAR) compares two compounded paths over the same aftermarket window:
Share buy-and-hold return = product of (1 + each share daily return) - 1
Benchmark buy-and-hold return = product of (1 + each benchmark daily return) - 1
BHAR = share buy-and-hold return - benchmark buy-and-hold return
"Product" means multiply the factors together. BHAR is the difference between the two wealth gains; it is not the product of daily abnormal returns and is not the ratio of final share wealth to final benchmark wealth minus one.
CAR and BHAR can differ because one adds daily differences and the other compounds the separate paths. Neither includes the allocation-price gain when the window starts at the first-day close. Neither is a trading recommendation or proof of risk-adjusted outperformance.
Worked example: placeholder numbers only
All figures in this section are invented placeholders for arithmetic, not an actual issuer, index, forecast or tracker record. Assume the same currency, no dividends or capital changes and complete official observations in a real implementation.
| Placeholder input | Value |
|---|---|
| Final offer price | 20.00 |
| Share closes on sessions 1, 2 and 3 | 22.00; 23.10; 20.79 |
| Benchmark closes before session 1, then on sessions 1, 2 and 3 | 1,000.00; 1,010.00; 1,030.20; 999.294 |
The placeholder first-day calculations are:
- Initial return:
22 / 20 - 1 = 0.10, or 10.00%. - Benchmark first-session return:
1,010 / 1,000 - 1 = 0.01, or 1.00%. - Market-adjusted initial return:
0.10 - 0.01 = 0.09, or 9.00 percentage points.
For the placeholder session-1 close to session-3 close aftermarket window:
| Interval | Share return | Benchmark return | Daily abnormal return |
|---|---|---|---|
| Session 1 close to session 2 close | 5.00% | 2.00% | 3.00 percentage points |
| Session 2 close to session 3 close | -10.00% | -3.00% | -7.00 percentage points |
- CAR:
0.03 + (-0.07) = -0.04, or -4.00 percentage points. - Share buy-and-hold return:
1.05 * 0.90 - 1 = -0.055, or -5.50%. - Benchmark buy-and-hold return:
1.02 * 0.97 - 1 = -0.0106, or -1.06%. - BHAR:
-0.055 - (-0.0106) = -0.0444, or -4.44 percentage points.
The placeholder offer-to-session-3 price return is 20.79 / 20 - 1 = 3.95%. That positive allocation-price result can coexist with a negative aftermarket result because the starting price differs.
Operating performance before and after listing
Share-price performance is not operating performance. We compare consolidated annual financial statements for the latest full fiscal year ending before listing and the earliest full fiscal year starting after listing. The fiscal year containing the listing is labelled separately and is not silently treated as a wholly post-listing year. These are fiscal-year comparisons, not equal-length windows around the listing date.
| Measure | Formula | What we compare |
|---|---|---|
| Revenue growth | current annual revenue / preceding comparable annual revenue - 1 |
Growth in the pre-listing year versus growth in the post-listing year; each needs its own preceding-year revenue |
| Operating margin | reported operating profit / revenue |
Pre- and post-listing margins, with the change in percentage points |
| Debt-to-assets | interest-bearing debt including lease liabilities / total assets |
Pre- and post-listing year-end leverage, with the change in percentage points |
Pre/post change = post-listing ratio - pre-listing ratio
Multiply this difference by 100 to display percentage points. Do not divide the post-listing margin by the pre-listing margin and call that a margin-point change.
Placeholder financial numbers only; all amounts use the same invented currency and unit:
| Input or result | Pre-listing full fiscal year | Post-listing full fiscal year |
|---|---|---|
| Revenue in the preceding comparable year | 100 | 150 |
| Revenue in the selected year | 120 | 165 |
| Operating profit | 12 | 19.8 |
| Interest-bearing debt including leases | 30 | 24 |
| Total assets | 150 | 160 |
| Revenue growth | 120 / 100 - 1 = 20.00% |
165 / 150 - 1 = 10.00% |
| Operating margin | 12 / 120 = 10.00% |
19.8 / 165 = 12.00% |
| Debt-to-assets | 30 / 150 = 20.00% |
24 / 160 = 15.00% |
In this placeholder comparison, growth changes by -10.00 percentage points, margin by +2.00 percentage points and debt-to-assets by -5.00 percentage points. The preceding-year revenue inputs belong to each selected year's own comparison period; they are not assumed to be consecutive pre/post listing years. These are arithmetic illustrations, not company findings or evidence that listing caused an improvement.
We use reported operating profit rather than mixing it with adjusted EBITDA. Debt includes current and non-current borrowings and lease liabilities without double counting amounts already included in a reported total. If the issuer's presentation does not support that definition, the leverage measure is no official data. A different sector-specific ratio would need its own label and methodology.
Revenue denominators and the preceding revenue used for growth must be positive; total assets must be positive. Negative operating profit is valid, but a zero or negative denominator does not produce a usable ratio under this policy. Missing components do not become zero.
The comparison needs consistent currency, units, consolidation scope, accounting policies and annual-period definitions. Restatements are versioned, not overwritten without a trace. Acquisitions, disposals, IPO proceeds and debt repayment can change the ratios without showing an improvement in the underlying business. We flag such changes and withhold a non-comparable pre/post difference rather than infer organic growth or claim that the IPO caused the change. Prepare the reporting trail with the first 100 days checklist.
Choosing and keeping a benchmark
The default is a broad equity-market benchmark relevant to the listing venue, in the same currency and return basis. The exact index, provider, series identifier, closing convention and selection reason must be recorded before its performance is used. No particular index is approved for ingestion or public display by this page.
A sector or size comparator may be useful as a separately labelled sensitivity view. It is not a replacement selected because the main comparison looks inconvenient. We do not choose peers with hindsight, use only today's surviving constituents or switch benchmark mid-window without versioning and a visible explanation.
The share and index observations must match the venue-session dates and documented closing cutoffs. Different holidays, stale prices or incompatible currency or dividend treatment are grounds to withhold the comparison, not to carry forward a level silently. We do not estimate a pre-IPO beta for a share with no trading history. A simple benchmark subtraction is not a market-model alpha.
Survivorship bias and interrupted histories
The coverage universe is retained independently of whether a company still trades. Delistings, failures, suspensions and acquisitions stay visible with their lifecycle status. Withdrawn offers remain calendar records but do not enter a listed-IPO return cohort.
A missing delisting payoff is not a zero price, and the last traded price is not necessarily an investor's terminal proceeds. A verified terminal outcome may support a separately dated terminal-window result. Until a complete continuation policy is implemented, a delisting before the requested endpoint makes that full-horizon result no official data; we do not pretend the final quote extends to the endpoint.
Any cohort summary must show the eligible universe, usable observations and unavailable observations with reasons. An equal-weighted average describes only the disclosed usable subset, not all IPOs. It must not hide missing failures or suggest that an incomplete curated universe covers an entire market.
Data gaps: no official data
A real observation needs an official issuer filing or announcement, exchange publication or index-provider source, a precise document or series location and a retrieval timestamp. A derived metric links to all input observations and the calculation version; an official source need not publish our arithmetic result itself. Publication also requires permission to use and display the underlying data.
We show no official data when a required input is missing, conflicting, not yet available, restricted from use, non-comparable or unsupported by the calculation. The accompanying reason distinguishes, for example, "horizon not reached", "benchmark unavailable" and "not applicable — no offer price". An unofficial quote is not used to fill the gap. Zero is a verified value only, never a substitute for null.
We do not interpolate, extrapolate, forward-fill suspended prices or treat silence about dividends as confirmation that none occurred. Corrections retain the previous observation and trigger a new calculation version. A last-verified timestamp is not a claim that the series is current.
How the tracker will show this
The planned deal page will separate:
- Offer-to-close price returns: first session and later session endpoints, each with its actual date and offer-price basis.
- Market comparison: the initial-return adjustment, named benchmark and its explicitly stated first-session interval.
- Aftermarket analysis: CAR and BHAR from the first-day close, the endpoint, session coverage and price or gross total-return basis.
- Business results: pre/post fiscal-year dates, growth, operating margin and debt-to-assets, with comparability notes.
- Evidence: source links, retrieval times, calculation version and a visible reason wherever no official data is shown.
The module will not display a synthetic performance history while data access or verification is incomplete. This methodology is educational; it is not investment advice.
Sources and scope
The formulas and window choices above are ipo.zone measurement conventions. No empirical IPO-return averages, legal thresholds or fees are asserted. The worked numbers are placeholders only.
Official conceptual reference: MSCI — How is an index constructed?, section "Calculating index value and returns"; retrieved 28 October 2026. This distinguishes price and dividend-inclusive index returns. It is not a licence to collect or redistribute index levels and does not endorse ipo.zone's benchmark choices.