Ever since it opened, the Cosmopolitan has been the place to be on the Strip. No question. Some have even taken to calling it the “Hard Rock Killer” because of its younger crowd appeal and impressive list of musical acts. If you’ve been there, you no doubt noticed: Cosmo feels busy.

Turns out that as you were waiting for the valet or to get into that concert, another story was brewing, one that should have Strip partiers very concerned—the $3.9 billion Cosmopolitan lost $139.5 million in its first 17 days.

Naturally the property’s spokespeople were quick to point out that figure from the last two weeks of 2010 included $116.5 million in “preopening expenses.” They expressed optimism that, without those expenses, the Cosmo actually netted $10.6 million over the same period.

Still, $139.5 million is enough to raise eyebrows, especially when you consider that all of CityCenter reported an operating loss of $255 million for the entire first quarter of 2010—and that includes a ongoing production show, Viva Elvis!, and a building that isn’t even being used, the ill-fated Harmon.

Whether or not the Cosmo begins turning a profit by the end of this year is a huge question mark, but there is reason to believe it will happen, at least if it follows its neighbor’s example. After two quarters of losses totaling $383 million, CityCenter finally posted a profit in the third quarter of 2010, with a net revenue of $413 million.