Facebook market plunge:

The social media giant’s stock suffers its worst loss in four years in the Cambridge Analytica scandal.

NEW YORK» Facebook plunged to its worst loss in four years Monday and led a rout in technology companies. The social media company’s stock fell following reports that a data mining firm working for the Donald Trump campaign im- properly obtained data on 50 million Facebook users.

The drop in Facebook stock came after The New York Times and the Guardian reported that the firm, Cambridge Analytica, was able to tap the profiles of more than 50 million Facebook users without their permission.

Elsewhere, the British pound rose and European stocks slumped after Great Britain and the European Union said they are getting closer to a deal that will complete Great Britain’s departure from the EU in March 2019.

The S&P 500 index sank 39.09 points, or 1.4 percent, to 2,712.92. The benchmark index took its biggest loss since Feb. 8, when it tumbled almost 4 percent as investors worried that rising inflation would slow the progress of the market and the U.S. economy.

The Dow Jones industrial average fell 335.60 points, or 1.3 percent, to 24,610.91. During the day it fell as much as 493 points. The Nasdaq composite gave up 137.74 points, or 1.8 percent, to 7,344.24. The Russell 2000 index of smallercompany stocks declined 15.49 points, or 1 percent, to 1,570.56.

Larger technology companies including Apple and Microsoft fared worse than smaller ones. Another market favorite, Amazon, also dropped, and health care stocks fell more than the rest of the market.

Representatives of Great Britain and the European Union said they made progress on the terms of Great Britain’s exit from the bloc. Great Britain is scheduled to leave the EU on March 29, 2019.