During the week of November 1, construction materials industry leaders U.S. Concrete and Martin Marietta released their 3Q 2015 earnings reports. Each company delivered strong growth in both revenue and earnings, but the market response to each’s results could not have been more different. While U.S. Concrete shares realized a 9 percent increase in pre-market trading following its earnings release, Martin Marietta’s stock dropped 8.5 percent following its announcement.

Is the largest potential deal in aggregates industry history—a merger between Swiss-based Holcim and French-based Lafarge—really at risk? At question in the merger is a growing gap in performance. Initially structured to be a 1:1 share exchange, strong performance by Holcim and currency movements have raised Holcim’s value to nearly $25 billion. Lafarge is currently valued at just over $20 billion. Accordingly, the original terms of the agreement are now less favorable to Holcim shareholders, a number of whom have been anonymously sourced as wanting more favorable terms that better reflect current market conditions.