Playing With Crispr, Investors Get Burned

It may seem obvious, but it’s a lesson that never seems to stick with biotech investors: Assigning billions of dollars in value to a medical innovation that’s barely been tested in humans isn’t the greatest idea.

For those who need to learn the hard way, a fresh reminder came Monday. Shares of companies tied to a heavily hyped, but unproven, gene-editing technology called Crispr were sent reeling after two studies published in Nature Medicine found a potential cancer risk.