Every international phone call passes from one carrier to another, and in the 1990s those handoffs ran on slow, private deals. Arbinet turned that market into an exchange. Carriers posted the routes they could offer and the prices they would pay. Arbinet matched them, routed the traffic and settled the bills. It went public in December 2004, as voice-over-IP cut the cost of calls and carriers hunted for cheap routes.

Minutes as a Commodity

Arbinet treated phone minutes like any other commodity. Its platform let a small carrier in one country reach buyers it would never meet in person. Arbinet took on the credit risk and the settlement, and it earned a fee on each minute traded. The model worked best when many small, nimble carriers wanted global routes. They could trade on one exchange instead of signing dozens of separate contracts.

Thin Margins, Long Lines

Arbinet priced its shares at $17.50 in December 2004, above the range it first set, and listed on Nasdaq as ARBX. Volume on the exchange grew. The price of each minute kept falling as calls moved to the internet and to mobile phones. Arbinet spent the next years adding services and cutting costs. In 2011 Primus Telecommunications acquired the company, and Arbinet's run as a public company ended.

Cover: The Bourse, Th. Schuhmann. Art Institute of Chicago, public domain. Chosen for the bourse (an exchange for calls).