Other big gainers last month included Accelerate Diagnostics and Natera, and share prices of 23 of the 27 companies in the index increased month over month.
The broader market drove down the stock prices of many diagnostics companies. Natera, Guardant Health, and CareDx paced the gainers.
The company's first quarter revenues were driven by sales of its noninvasive prenatal screening and carrier screening tests.
The firm is selling more than 5.2 million shares at an offering price of $19 per share.
The firm expects to offer nearly 5 million shares and also noted that this week it entered into an amended credit facility.
The company filed its first suit against Natera in March, claiming the firm's kidney transplant test infringes patents underlying CareDx's AlloSure test.
A study of 10 commercial labs offering NIPT in the US found that none followed all recommendations for reporting results and informing patients and providers.
Clinical researchers at AACR discussed a wide range of approaches focusing on several different potential use-cases in the detection or assessment of early cancers.
The number of gainers outpaced decliners 21 to six, and the index outpaced the Dow Jones Industrial Average, the Nasdaq Composite, and the Nasdaq Biotech.