All but one of 37 companies based in Iowa or running major operations here saw their stock prices fall in December, a Business Record analysis found.

United Fire Group Inc. was the lone winner, posting a 2.93 percent gain. The stock price drops at the remaining companies on the list ranged from 0.41 percent at EMC Insurance Group Inc. to 30.56 at Windstream Holdings Inc. and 30.47 percent at KemPharm Inc., the Business Record's monthly snapshot of Iowa companies shows. 

Rockwell Collins was acquired by United Technologies Corp. The merger went through on Nov. 26. The final stock price for Rockwell Collins was $141.04. After the merger, Rockwell Collins was removed from the Iowa Index.

The Iowa Index, an unweighted average price of 21 Iowa-based public companies, dropped 7.15 percent in December — compared with a 9.48 percent drop in the Nasdaq stock index and an 8.66 percent fall in the Dow Jones industrial average.

Comparing December 2018 with the previous December, the drop was 21.2 percent. But more companies were in positive territory in that comparison, with United Fire up 21.6 percent December over December. Renewable Energy Group in Ames did even better, with a 117.8 percent gain December over December. Workiva was up 67.7 percent, Casey’s 14.5 percent, Windstream 12.97 percent, and EMC 11 percent. 

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