A stock market data error this evening set an undetermined number of companies listed on the Nasdaq exchange to a share price of $123.47, sending some tech companies’ stock prices crashing and others’ soaring. In a statement obtained by the Financial Times, Nasdaq said the culprit was “improper use of test data” that was picked up by third party financial data providers. The exchange said it was “working with third party vendors to resolve this matter.”

The issue was replicated across major financial websites, including Bloomberg, Google Finance, and Yahoo Finance, and it’s not known when it all started. But stock notifications for tech companies started pouring in at some point this evening, resulting in quite a few tweets on the matter:

The @NYSE API is informing the world that a bunch of stocks just got set to $123.47 or so. That seems...not good. pic.twitter.com/X33l7kt0QQ — Danny Ben-David (@primunomina) July 4, 2017

Seems like all systems are running at 123.47% over at good ole' @NYSE! pic.twitter.com/2IvhkVaISk — Anil Dash (@anildash) July 4, 2017

For a company like Amazon, which enjoyed an opening price of $972.79 a share, the error has had a catastrophic effect on the appearance of its market cap. For other companies, like struggling Facebook game maker Zynga, the error is a bit of good news, if only for the fleeting perception of improbable success:

Update 10:55PM ET, 7/3: Included Nasdaq’s statement on the matter attributing the error to an “improper use of test data.” The headline of the article has also been updated to reflect this.