Every new DSL line had to be connected and tested by hand, in crowded phone company central offices. Turnstone Systems built equipment that did that work remotely. Phone companies and their new rivals were racing to sell DSL, broadband delivered over old copper phone lines. When Turnstone filed to go public at the start of 2000, DSL was spreading fast. Its customers were raising money at a remarkable pace.

The Central Office Bottleneck

Turnstone bet that the DSL boom would create a bottleneck in the central office, where technicians had to connect and test each copper line. Its equipment let carriers switch and test lines from afar, which saved truck rolls and time. Many of its biggest customers were the competitive local carriers born after the Telecommunications Act of 1996. Turnstone's fortunes rose and fell with theirs.

Wound Down, Cash Returned

Turnstone priced at $29 a share in February 2000, and investors valued it richly at first. Within a year, many of the young DSL carriers it served ran out of money and failed. Much of Turnstone's demand went with them. The company chose to wind down instead of chasing a shrinking market. Shareholders approved a liquidation, and Turnstone returned its remaining cash in a series of payouts.

Cover: Plovers, full moon, and waves, Utagawa Hiroshige. Art Institute of Chicago, public domain. Chosen for shorebirds over moonlit waves (the turnstone).