CareDX Inc. /zigman2/quotes/200138382/composite CDNA -2.43% shares surged 17% in the extended session Thursday after the company reported second-quarter earnings. The company reported second-quarter net losses of $14.1 million, or 40 cents a share, compared with losses of $4 million, or 19 cents a share, in the year-ago period. Adjusted for changes in the value of stock warrants and derivative liabilities losses were 4 cents a share, narrowing from 17 cents a share in the year-earlier period. Revenue rose to $17.8 million from $12.1 million in the year-ago period. The company said it expects full-year sales of $68 million to $70 million. CareDX shares have gained 104% this year, with the S&P 500 index /zigman2/quotes/210599714/realtime SPX +0.02% rising 6.7%.