Guardant Health CEO Helmy Eltoukhy told CNBC on Thursday the company's liquid biopsy, Guardant360, is a "big game changer" when it comes to the detection of cancer.
The Silicon Valley oncology company, backed by SoftBank, sold 12.5 million shares at $19 in its initial public offering Thursday.
Less than an hour before close, the stock was trading at $34.37 per share.