In a long awaited move, Archipelago, one of the first electronic stock exchanges, has filed for an initial public offering. The move could force the hand of The New York Stock Exchange and the Nasdaq Stock Market. The Chicago-based exchange, which began its existence as an ECN, or electronic trading network, could raise $150 million in the offering. The stock will trade under the ticker symbol ARCA, and will be listed on Archipelago's own exchange. In filing for an IPO, Archipelago is not the first stock exchange or ECN to go public in the U.S. Instinet ( INGP), the granddaddy of ECNs, went public several years ago. Last year, the Chicago Mercantile Exchange ( CME) went public in a highly successful IPO. The company's filing shed the first real look at its finances. Last year it turned profitable for the first time in its brief operating history. In 2003, Archipelago earned $1.3 million, after posting over $100 million in losses during the prior three years. Archipelago took in $458 million in revenues, of which $428 million were transaction fees that come from electronically matching buy and sell orders. The exchange's biggest stockholder is Goldman Sachs ( GS), which owns 9.5 million shares, or 28% of the company. Goldman also is one of the lead underwriters on the IPO, along with J.P. Morgan Chase ( JPM), another stockholder. Other significant owners include GAP Archa Holdings, Fidelity, Credit Suisse First Boston, Merrill Lynch ( MER), Instinet and E*Trade ( ET). GAP Archa Holdings is part of Archipelago.