How the numbers are computed
The market inputs on isk.gg come from ESI. This page states the arithmetic isk.gg runs on top of those inputs, value by value. Prices are stored and computed to 0.01 ISK, while the interface may shorten them only for display.
Two kinds of source data
Order collection is scheduled every five minutes and publishes only after a complete cycle. Daily history collection starts after noon UTC and retries incomplete regions through the day. Each history day carries an average price, the highest and lowest trade, the traded volume and the count of active orders. The data page covers where both come from.
The two families never mix. Order numbers follow your Market Scope and the table filters. History numbers are measured per region and ignore order filters.
A requested history window ends on the newest complete day shared by the history sources it needs. During the daily refresh that end date can move back so old and new sources are not mixed. If retained coverage cannot fill the whole span, affected values show a dash.
Exclude scams is a rough outlier heuristic. Within the selected Market Scope, sell orders above ten times the item's sell median and buy orders below one tenth of its buy median are dropped before the affected depth, volume and count metrics are computed. Cheap sells and generous buys remain visible, but misleading orders can still pass the heuristic.
The item table
The groups page explains what each column is for. This is the arithmetic behind it. Every numeric column answers with one number in every scope. Order columns pool every order in your Market Scope, one region or many. History columns combine the regions behind your scope, each weighted by its traded volume. A system, station or structure scope reads its parent regions, and All Regions runs the same math over every region. Supply and Demand divide one family by the other.
- Sell
- the lowest sell price among the orders in scope
- Buy
- the highest buy price among the orders in scope
- Spread
- Buy minus Sell, in ISK. A normal uncrossed order book is negative. The two orders can be at different stations in your scope, and no fees, taxes, hauling or execution risk are subtracted, so this is not guaranteed profit.
- Spread %
- Spread divided by the Sell price
- Average
- the volume weighted mean price over the selected period. Each traded day contributes its price times its volume, and the total is divided by the total volume.
- Change
- the price move across the selected period. The start and end prices are volume weighted averages over the first and last quarter of the period, and an item with too little trading in either quarter shows a dash instead of a guess. With several regions selected, every region must have enough trading on its own.
- Change %
- Change as a share of the period's starting price
- Trend
- the period's daily average prices drawn as a small line in the Item cell. Its color follows the sign of Change %.
- Daily Value
- ISK traded over the period divided by the days in it, quiet days included
- Daily Volume
- units traded over the period divided by the days in it, quiet days included
- Supply
- Sell Volume divided by Daily Volume, in days. How long the resting stock lasts at the recent trade rate.
- Demand
- Buy Volume divided by Daily Volume, in days. The same reading for the buy side.
- Sell Volume
- the units resting on sell orders in scope
- Buy Volume
- the units resting on buy orders in scope
- Sell Orders
- the count of live sell orders in scope
- Buy Orders
- the count of live buy orders in scope
The summary cards
Under a region, system, station or structure scope the cards leave PLEX out, so the one global market does not tilt a local reading. All Regions includes it.
- Change
- the average of each item's period price move, weighted by its Daily Value. Items without enough trading evidence stay out of the average.
- Coverage
- the share of the table's Daily Value that had enough evidence to be counted in Change
- Value
- the sum of Daily Value across every item in the table with a live order in scope
- Concentration
- the share of Value held by the biggest items. The top 5 in a large table, fewer in a small one.
The history panel
Chart History draws these values and Table History lists them day by day. The numbers are the same in both modes, so every case below applies to both.
- Average
- the day's average trade priceOne regionas publishedSeveral regionsone line per region, each as publishedAll Regionsthe volume weighted mean across every region
- High / Low
- the day's highest and lowest trade pricesOne regionas publishedSeveral regionsa band per region, each as publishedAll Regionsthe single highest and the single lowest across regions
- Volume
- the day's traded unitsOne regionas publishedSeveral regionsone bar per region, stackedAll Regionstheir sum
- Orders
- the count of orders active that day. It counts orders, not trades.One regionas publishedSeveral regionsone value per regionAll Regionstheir sum
- 7D MA
- the plain mean of Average over the trailing 7 calendar days. Days without trades add nothing and are never counted as zero.One regionthe mean of that region's AverageSeveral regionscomputed separately for every lineAll Regionsthe mean of the combined Average
- 28D MA
- the same mean over the trailing 28 calendar days, following the same scope rules
The order tables
Each row represents one current ESI order. The items page walks the columns one by one. Price is stored to 0.01 ISK and may be shortened only for display. Volume, Min, Range, Issued and the location columns come from the order, and only three cells involve any further arithmetic.
- Expires
- the order's issue date plus its duration
- Cargo
- the m³ readout on a row is the order's remaining units times the item's packaged size
- Security
- shown rounded to one decimal the way the EVE client rounds it, so a system just above zero still shows 0.1
Order depth
The depth chart is two running totals over the live order tables. The Sell curve shows how many units are available at or below each price. The Buy curve shows how much demand rests at or above it. The table filters apply before the totals are built.
The ticker
- Price
- the lowest live sell in your Ticker Scope
- Percent
- the distance of that sell from the item's latest daily average price, as a share of that average. At region scope both readings use that region. At system, station or structure scope the live sell is local while the comparison average comes from the parent region. It is a deal signal, not a period change, so a single deeply discounted order shows a large negative number on purpose.
- PLEX
- the pinned row reads the global PLEX market with the same formula
Everything else
- Scope pickers
- regions, systems and stations rank by their live order count, busiest first
- Group counts
- a group's badge counts the items inside it with a live order in your Market Scope, child groups included
- Online
- the users with isk.gg open right now
Free, without an account
The Market Browser is free and carries no ads. Reading the market needs no login, the data comes from EVE's official ESI rather than from any account of yours, and everything you save stays in your browser.
Open a table and check any of it yourself.
Live orders across 70 K-space regions, plus the Global PLEX Market, for about 18,000 item types, with history up to 365d.