Covid-19 sent companies that have developed and sold tests to diagnose the condition spiraling, wiping out about $38 billion in market value across more than a dozen stocks.Concerns about the sustainability of profits for the testing-kit market erased about a third of Quidel Corp.’s value.
High-flying stocks including Hologic Inc. and Qiagen tumbled 8% or more, while competitors like Thermo Fisher Scientific Inc., Abbott Laboratories, and Danaher Corp.
shed billions in value as their stocks faded.Some industry watchers had been optimistic for the group’s resilience despite advancements for vaccines and therapies to combat the coronavirus.