How this index is calculated
The lug²lug market index measures asking prices in the enthusiast secondhand market — the listings on r/Watchexchange and WatchUSeek, where collectors sell to each other. That is a different market from the dealer and auction flow the other published watch indices measure, and this page is the full statement of how ours is built, what it can support, and what it cannot.
What it measures
Asking prices, not sale prices.
A sale price is never observed. Forum sellers do not publish what they accepted, and we do not infer it. Everything on this surface is what somebody asked.
Two panels, built separately, never blended.
The listing-ask panel is every asking price matched to a catalog reference, live or closed. The closing-ask panel is the last price a seller asked before their listing closed. A closed listing may have been withdrawn rather than bought, so the second is still not a sale price — it reads a little high, and it exists as an independent cross-check rather than as an improvement on the first.
A listing counts only when it is matched to a catalog reference.
A post that cannot be resolved to a specific watch in the lug²lug catalog is not in the panel at any stage. This is what makes the index a matched-model index rather than a price average over whatever happened to get posted.
Nothing before 2022.
Older forum threads exist only where nobody pruned them, and the direction of that survivorship bias is unknown. The index is indexed to 2022 = 100 and does not extend behind it.
How a year's figure is built
Matched model.
A year’s change is the average change across watches listed in both that year and the one before. A watch that appears for the first time this year contributes nothing to this year’s change — which is why a newly crawled brand can never move the line on arrival.
One vote per watch. Nothing is value-weighted.
Every matched watch contributes equally regardless of price. A dollar-weighted index of this panel would be a tracker for whichever brand happens to list the most expensive watches, which is a different measurement wearing this one’s name.
Per-watch prices are aggregated before they are compared.
Within a window, a watch’s many listings collapse to one figure per window, so a single heavily reposted listing cannot outvote the rest of the panel.
Intervals come from a bootstrap clustered by watch.
The 95% interval printed beside every figure is a bootstrap interval resampled at the level of the watch, not the listing — listings of the same watch are not independent observations, and treating them as if they were would produce intervals several times too narrow. Extreme relatives are winsorized before the mean, and impossible ones are dropped; both counts are stored with the point.
Levels are chained, and the chain is honest about breaking.
An index level is the product of the yearly links, starting from 2022 = 100. Where a year cannot publish a link, the level chain cannot continue through it, and no level is drawn rather than a gap being bridged with an assumption. That is why about a third of the cuts show a year-by-year ladder and no level line.
Annual only.
There is no quarterly, monthly or weekly line anywhere on this surface, not even as an unlabeled sparkline. Measured quarterly standard errors run several percentage points against quarterly moves of a few percent, so a quarterly line would be a picture of our own sampling noise.
When a figure is published
A cut has to earn its number. The floors are fixed in the series registry and are not lowered to make a page look fuller.
- 40 matched watches in both years before a cut may publish a point estimate.
- 25 matched watches before it may publish a range.
- 120 matched watches for the overall index, which is a stronger claim and carries a stronger floor.
- Below 25, the cut publishes its coverage and says nothing about direction.
A wide interval on a large panel is a finding, not a failure. A reading of −0.6% with an interval of ±2.0 points on a thousand matched watches is a precise flat — it says the market did not move, and it says so with more confidence than most published watch figures say anything.
The five verdicts
Every figure on this surface is gated by a verdict computed when the index is rolled up and stored with the point, so no client re-decides one. The five are different kinds of answer, not five renderings of one answer.
| Verdict | What you see | What it means |
|---|---|---|
| moved | A signed percentage, e.g. +7.4% | The 95% interval excludes zero. This is the only verdict allowed to use a directional word. |
| held | “No clear move”, with the interval | The interval is tight and straddles zero. That is a real answer, not a missing one: the group did not move enough to be detected. |
| band_only | A range, e.g. −14% to −4% | Enough watches for a range, not enough for a centre. The point estimate is withheld on purpose: readers anchor on a centre regardless of the interval printed beside it. |
| unclear | “Not enough to call it”, and no interval | A figure exists behind the year and is not steady enough to publish. The interval is withheld too — publishing the band under a reading we refused to publish would be the same claim through a side door. |
| coverage_only | The count alone | The panel size is publishable; the move is not. Below the publication floor, nothing about direction is said. |
Against the index, not against zero
Every cut on this surface is a subset of the same panel. That has a consequence people miss: a cut’s absolute figure is mostly the whole market’s move wearing the cut’s name. In one recent year-to-date pass, thirty-two cuts cleared the significance bar and every one of them was positive — one common factor printed thirty-two times.
So each cut also reports its change minus the change in the index it belongs to, measured on the same watches in the same pass, with its own interval and its own verdict. That second line is the part that is about the cut rather than about the market.
It is a difference between two asking-price changes. It is not a return, it is not a yield, and it is not advice. It is also never colour-coded: rising asking prices are good news for a seller and bad news for a buyer, so a green-up chart is wrong for half the audience on every render.
The cuts
Beyond the overall index, the panel is cut six ways: by brand, by kind of watch, by price band, by case size, by movement, and by whether the watch is still made. Each published cut gets its own page with its full history.
A brand is one cluster.
Watches from one brand move together, so a brand cut carries much less independent information than its count suggests. That is why most brand cuts publish a range rather than a number even when their panel looks large.
Price bands are set from market price, not retail price.
A watch is in the under-$500 band because of what it goes for secondhand, not because of what it cost new. That is also why price-band pages carry no list of the watches in them: naming the members would publish each member’s market price, and per-watch prices are not part of this free surface.
Cuts are not re-keyed by reference.
Keying the panel by (brand, reference) instead of by catalog watch was built and tested, and it does not produce a catalog-free key. The panel remains keyed by the catalog watch.
Revision and freezing
The current year is provisional and revises monthly.
A year-to-date reading widens its window every month, so it moves. It is marked provisional wherever it appears.
A closed year freezes, and a frozen figure that changes must declare it.
Forum listings backfill for weeks after a window shuts, so an annual figure genuinely moves for a while. A point freezes after its window has been closed long enough for that to settle. After that, a published figure that changes has to be recorded as a restatement with a reason — because the one sentence a competitor gets to say otherwise is “their 2024 number changed after we quoted it”.
Every publication is kept.
Each published vintage of a point is appended to an immutable record, so what a figure said on the day it was quoted remains recoverable.
What this index cannot tell you
It cannot tell you what a watch sold for.
No sale price is observed anywhere in this pipeline. If you need transaction prices, this is not that measurement.
It cannot tell you what one specific watch will do.
Per-watch annual moves are dominated by sampling noise at this panel size — measured at roughly the size of the moves themselves. No per-watch trend line is drawn anywhere on this surface. The only per-watch rates published at all are the handful whose interval clears zero, and they are labelled as such.
It follows the same watches getting older.
A matched-model index of used goods carries some drift from age alone, and that drift is not measured out. Read a figure as what an owner holding these watches saw, not as what the model is worth new.
It is not the luxury market.
The panel is what enthusiasts list to each other, which skews to microbrands, Japanese brands and the sub-$2,000 field. Rolex carries a fraction of the matched references Seiko does here — not because Rolex is small, but because Rolex trades mostly through dealers and auctions, which is not the market we measure. Read a Rolex cut here as “what forum sellers asked”, never as “the Rolex market”.
It is not investment advice.
This is a measurement of asking prices in one corner of one hobby. It is not a return, not a valuation, and not a recommendation to buy or sell anything.
Questions, corrections, or a figure that looks wrong? contact@lug2lug.org. Full site disclosures are at /disclosures. The index itself is at /market.