A who’s who of government, business and international finance lost a total of more than $600 million they had invested in scandal-plagued Theranos Inc., according to previously sealed documents made public in a lawsuit.

High on the list is Education Secretary Betsy DeVos, whose family invested $100 million in the Silicon Valley blood-testing company, the documents show. Mrs. DeVos had previously disclosed that her family was a Theranos investor in a government filing, but the size of the investment wasn’t known.

“The...