Why Shares of Guardant Health Dropped 33.6% in May

It's a bit early for investors to jump the ship regarding Guardant because the biotech stock still has plenty of good long-term prospects. The test will compete with the Galleri blood-based cancer screening by the Grail unit of Illumina and a the Cologuard fecal screening by Exact Sciences. Investors are also watching the outcome of a lawsuit, filed in March by Illumina, that claims that Guardant and two of its founders -- former employees of Illumina -- used Illumina's propriety information to help them launch Guardant.