EBay Inc. moved billions of dollars worth of merchandise in each quarter of 2006, but investors used to years of astronomical growth just couldn’t get excited about moderate forecasts or slowing expansion amid growing competition in the U.S. and abroad.

EBay’s shares lost nearly 7 percent through mid-April but really began their descent on April 19, when the company failed to raise its earnings outlook for the remainder of the fiscal year, even though first-quarter results came in slightly ahead of the company’s expectations.

The company cited a plan to increase spending in Korea, where local e-commerce company Gmarket Inc. excels. Gmarket went public in June, and Yahoo Inc. owns a minority stake.

Local competition also plagued eBay in China, pushing the company to shutter most of its own operations and take a minority stake in an auctions joint venture with a local technology company, Tom Online Inc.

The stock tumbled lower over the summer as eBay struggled with slowing growth in “core listings,” or regular auctions posted on the main site.

In recent quarters, core listings weakened as sellers offered more of their wares in “stores,” or customized Web pages on eBay where shoppers could buy items right away, instead of bidding.