Looking for a way to invest in the "biggest biotech discovery of the century" -- CRISPR gene editing? Two of the top candidates are CRISPR Therapeutics AG (NASDAQ: CRSP) and Intellia Therapeutics, Inc. (NASDAQ: NTLA). Both biotechs are focused on harnessing CRISPR gene editing to fight disease.CRISPR Therapeutics is the hands-down winner in terms of stock performance so far in 2018.