Methodology

PriceTickers shows how prices of entire US consumer product markets develop – just as a stock index summarizes the performance of a market. Every product with a UPC or EAN is its own ticker with a price chart.

Data sources

We collect offers for 14 product markets several times a day from eBay (US marketplace, items located in and shipping to the United States). For each offer and day the lowest price is stored in US dollars – new items only, before sales tax and excluding shipping. We do not sell anything ourselves and retailers cannot pay to influence an index.

Amazon.com: Under the Amazon Associates Program terms, Amazon prices are not tracked over time and are not part of any price history, chart, index, key figure or price movement. On product and search pages we show Amazon offers only as the current price – never more than 24 hours old and always with the date/time it was retrieved. eBay: every eBay offer shows when we last retrieved it. Prices and availability are accurate as of the date/time indicated and are subject to change; the price shown by the retailer at the time of purchase applies.

Which constituents count

A market index contains the market's main products: new items only, no accessories and no spare parts, duplicate offers of the same model merged, obvious misassignments (below 10% of the median price) removed. Only offers from established sellers count: eBay listings are included only if the seller has at least 100 ratings with at least 98% positive feedback (eBay does not flag business accounts in the US) – sellers with fewer or worse ratings are excluded, as are eBay listings with several variants but no UPC/EAN. Category indices use the same selection rules and are created from eight constituents.

Calculation

• Chaining: For each day the price ratio today/yesterday is formed for every constituent that has a price on both days. New or disappearing products therefore do not distort the index.
• Average: Geometric mean of the ratios (Jevons index) – robust against individual outliers and without the upward bias of a simple average.
• Outliers: Daily changes above +50% or below −33% are treated as data errors (variant, accessory) and do not count. Short gaps of up to three days are bridged with the last price.
• Minimum size: If a day has fewer than five comparable pairs, the index remains unchanged.
• Base: 100 on 07/06/2026, the start of recording; markets that start later begin at 100 on their first day.
• Permanent record: Stored days are normally not changed retrospectively; only the last three days are recalculated. Exception: when a selection rule is corrected, all series are recalculated once from the start.

Sectors and the PriceTickers Index

Sector indices and the PriceTickers Index chain the geometric mean of the daily factors of their markets – each market counts equally, regardless of the number of its products.

• Energy & Power: Power Station Index, Energy Monitor Index
• Home & Garden: Air Conditioner Index, Grill Index, Pool Index
• Mobility: E-Bike Index, E-Scooter Index
• Tech & Gadgets: Smartphone Index, Laptop Index, Tablet Index, Game Console Index
• Fashion & Lifestyle: Sneaker Index, Watch Index
• Health: Vitamin Index

Biggest movers

The movers lists compare an offer's current price with the lowest price of the same product (same UPC/EAN, otherwise same brand and model) 1, 7 or 30 days earlier. A move is only listed if it is confirmed:

• the new price level has held for at least two days (7 and 30 days; within 5%),
• the product has a UPC/EAN ticker, or at least two offers of the same model are at the new price level (within 10%),
• without a UPC/EAN, changes of more than ±35% are not shown; with one, the limit is ±50%.

Product tickers (UPC/EAN)

A ticker's chart shows the daily best price across all eBay new-item offers with this code – even if the product is listed by several sellers. 12-digit UPC-A codes are shown as UPC, 13-digit codes as EAN. In the comparison all curves are normalized to 100 on the first day of the selected period. Pages for search engines only exist for tickers with at least 30 days of history or several sources.

How we make money

Buy buttons and price links are affiliate links (marked “Ad”): if you buy through them, we may earn a commission from the retailer at no extra cost to you. As an Amazon Associate we earn from qualifying purchases. Commissions never influence which products are included in an index or how they are ranked. See our affiliate disclosure.

Colors and limitations

Green means falling prices (good for buyers), red rising ones; every change is also shown with a sign (+, −, ±), so color is never the only cue. Product prices do not follow stock market rules: indicators such as moving averages or RSI are for orientation only. Prices and availability change frequently; always check the final price at the retailer. All information without guarantee; no purchase or investment advice.

Data as JSON

Every index series is freely available, e.g. /api/v1/index/wo or /api/v1/index/market:e-bikes.