Dexcom shares plunge more than 40% for worst day on record

Dexcom shares sank more than 40% on Friday, their steepest decline ever, after the diabetes management company reported disappointing revenue for the

and offered weak guidance.

The stock fell $43.85 to close at $64, wiping out more than $17 billion in market cap. Prior to Friday, the biggest drop came in September 2017, when the shares plunged 33% in a day. Dexcom held its stock market debut in 2005.

Dexcom’s revenue increased…