Marketplaces are buildings that implement in-game exchanges, and allow for the trading of raw resources, refined materials, and finished goods for SWAY and vice versa. Markets are built on asteroid lots and are local to that asteroid. Limit buy and sell orders, as well as market buy and sell orders, are supported in an order book (not AMM) style exchange. Players must select goods in an inventory on the same asteroid when placing a limit or market sell order, or select available space in an inventory on the same asteroid when placing a limit or market buy order. Limit buy and sell orders are not guaranteed to ever fill; that depends on the player-based economy!
One of the oldest cuneiform tablets that still exists is a complaint from one merchant to another about substandard copper being offered for trade. It seems little has changed over the last four thousand years.