Methodology
dates in Pacific Time (PT)
What this is
Secondhand Markets publishes daily statistics on active listings across eBay secondhand categories. Every number is derived from the asking prices of listings that were live on eBay when we observed them that day.
What it is not. These are not sale prices. We do not collect, model, or report what items sold for, how many sold, or any transaction or demand-side data. An asking price is what a seller is asking — not evidence of a sale.
Metric definitions
| Metric | Source | Definition |
|---|---|---|
| Ask Median | daily sample | The median asking price of the active listings we observed in this market that day. |
| Ask Band | daily sample | The middle 50% of that day's observed asking prices (25th to 75th percentile). |
| Market Size | category-wide | The total number of active listings eBay reports for this category (US-located, US-deliverable) — a category-wide count, not our sample. |
| Listings Observed | daily sample | How many listings we actually sampled from this category that day. |
| Fresh Share | daily sample | Of the listings in today's sample, the share first listed within the last day — a property of our sample, not market-wide inflow, comparable only against this market's own history. |
| Auction Share | daily sample | Of the listings in today's sample, the share running as auctions rather than fixed-price. |
A note on Fresh Share
Fresh Share is a sample statistic, never a market-wide rate of new supply. Our daily collection is ranked by eBay's default Best Match, which over-represents newly-listed items, so Fresh Share reads higher than the true share of new listings in the whole market.
It also depends on whenwe collect: the count covers items first listed on the observation date, so an early-morning run captures fewer hours of “today” than a late one. The collection time is therefore part of the metric's definition — and because the schedule is fixed in UTC (see Collection & data age below), the Pacific hour shifts by one at each daylight-saving transition. Fresh Share steps slightly at exactly those two boundaries. Compare Fresh Share only against a market's own history — never across markets.
Collection & data age
We collect once per day, each morning, Pacific time. The run is scheduled on a fixed UTC clock so that consecutive runs are exactly 24 hours apart; because the clock is fixed in UTC, the Pacific start time shifts by an hour at daylight saving, and it is an hour later during daylight saving than outside it. Charts and statistics reflect that daily snapshot. On the occasional day when the scheduled run does not fire and a backup run collects instead, the snapshot is taken later that morning.
Where individual active listings are shown, each carries a note of when it was observed. eBay's terms require a data-age disclosure for listing information older than six hours, and because collection is once daily, essentially every displayed listing is older than that — so the age is shown as a standing part of the interface, not fine print.
Condition
Listings are grouped into four condition buckets: New, Used, For Parts, and Unknown (where eBay reports no condition). Used includes refurbished; For Parts/Not Working is reported separately.
Gaps are gaps
Raw listing data lives only 24 hours, and eBay has no way to tell us what a market looked like on a day we missed. So a missed collection day is a permanent gap. Charts render gaps as gaps — we never interpolate or invent a value to bridge them.
Scope
Statistics reflect US-located, US-deliverable active listings within each market's eBay category. Category scoping and the US-seller filter make our Market Size read lower than eBay's unfiltered on-site counts — that is the number becoming more precise, not a discrepancy.