There seems to be some mysterious force that keeps stocks from holding on to trillion-dollar market caps. Only three months after Apple made history by becoming the first U.S. stock ever to be worth $1 trillion, the stock closed Monday below that milestone level.

Apple’s stock first surpassed the $1 trillion mark on Aug. 2 and has held above that level since then. According to Nasdaq, Apple has 4.83 billion shares outstanding. On Monday, Apple’s stock closed at $201.59 a share, 2.9% below its official closing price last week and low enough to give Apple a net value of $974.5 billion.

Apple made stock history by becoming the first U.S. company and the second company overall (after China’s Petrochina) to attain a market value of $1 trillion. Amazon briefly joined Apple into that elite club but has since lost more than 20% of its value.

Amazon’s market value rose above the $1 trillion level on Sept. 4, then dropped back below the following day. Since then, Amazon has continued to fall in part on concerns about a slower holiday season this year.

Petrochina, the first global member of the trillion-dollar club, reached that level on its first day of trading after its 2007 IPO. But that peak coincided with a Chinese stock-market bubble, and PetroChina's shares would lose $800 billion in value over the next 10 years.

Apple’s stock began declining last Thursday, after the company warned investors that its holiday sales could come in below Wall Street forecasts. In the current quarter, Apple said its revenue would come in between $89 billion and $93 billion. Analysts had forecast revenue of $93 billion.

That may not be more than a speed bump for Apple as it pushes to sell more iPhones and other devices, along with a growing business in services, like Apple Music and the App Store, to help revenue and profit grow in coming years. Still, not long ago, the U.S. stock market had two trillion-dollar stars.

As of Monday’s close, it has none.