what goes up must come down
Any person or thing experiencing a large rise or surge (e.g., in success, cost, popularity, etc.) will inevitably see a fall or return to normal. A reference to the law of gravity, that anything raised into the air will inevitably come back down to the ground. The toy exploded in popularity just before Christmas that year, with stores around the country having trouble keeping it stocked. What goes up must come down, however, and it faded into obscurity after just a few months. The financial growth these companies are recording is exponential, which has some analysts and investors worried—what goes up must come down, after all.
Farlex Dictionary of Idioms. © 2015 Farlex, Inc, all rights reserved.
What goes up must come down.
Prov. Anything that has risen or been raised up must eventually fall down. When it came time to move out of our second-floor apartment, we looked at our large, heavy sofa with dismay, not sure how we would get it down the stairs. “What goes up must come down,” my husband said, “Somehow.”
McGraw-Hill Dictionary of American Idioms and Phrasal Verbs. © 2002 by The McGraw-Hill Companies, Inc.