Sixteen out of 21 Iowa-based companies posted losses in the month of May. Five companies posted gains. 

EMC Insurance Group posted the only double-digit percentage gain for the month at 12.36%. United Fire Group Inc., KemPharm Inc., Workiva Inc. and NewLink Genetics Corp. posted single-digit percentage gains.

Four companies posted double-digit percentage losses, and 12 posted single-digit or smaller percentage losses. Renewable Energy Group had a 35.16% loss, Flexsteel Industries had a 20.82% loss, Meredith Corp. had a 12.25% loss and Lee Enterprises Inc. had a 10% loss.

The Iowa Index, an unweighted average price of 21 Iowa-based public companies, decreased by 4.91% from April and was down 15.31% on a year-over-year basis, the Business Record's monthly snapshot of Iowa companies shows. 

By comparison, the Dow Jones industrial average was down 6.69% and the Nasdaq was down 7.93% in May.

Corteva Agriscience successfully completed its separation from DowDupont as of June 1.

The Iowa-based companies that make up the Iowa Index are in bold in this list of companies with sizable operations in the state.

See the full Iowa Index