Trade demand
Ships only buy what they ask for. Each docked ship asks for one to three goods of the kinds it trades in, so some goods sell every few hours and others wait days for a buyer. Set your port level, traffic share and sell rule to see the odds for every good.
Ordinary goods
Sold to any ship that docks. The bar is how often ships ask for the good each day, on a square-root scale so rare asks still show; the bright part is the asks whose bid meets your sell rule.
Pad-class goods
Secure, hazardous, rare and exotic goods are asked for only by ships docked at a pad of their class. Class pads are medium pads, so only Light Haulers, Couriers and Tankers use them. The bar is the share of visits at that pad that ask for the good, on a square-root scale.
How the odds are worked out
- Ship visits a day = the class's base arrivals × your share of region traffic × the port level's factor (1, 1.1, 1.25, 1.4, 1.6, 1.8). A class visits only from its own level.
- Which goods a ship asks for: one to three, drawn without repeats from the goods it trades in, each weighted by its traffic weight; a good weighs nothing until its opening level, and at a class pad that class's goods weigh 8× more. The chances are simulated with the game's own draw, 200,000 visits per case.
- Will the bid meet your rule: a ship bids the exchange price × (1 + a premium drawn evenly from its range, see Ships), plus 20% for a pad-class good. A sale needs that bid to reach your sell rule.
- Wait per sale = 1 ÷ qualifying asks a day. A sale takes a share of the ship's free hold, so one sale can move a large lot.
Not counted: a ship never asks for a good it already carries, and a full hold asks for less; research that raises bids or adds goods per visit; your own stock does not move bids.