Shares of military contractors have hit a wall this year after two years of breakneck gains.

Traders are expecting the pain to deepen as they position for protracted negotiations and funding delays should Democrats take control of one or both houses of Congress following the midterm elections.

Defense stocks have lagged the broader market amid doubts about President Donald Trump’s ambitious Pentagon budget and steep valuations. Companies make tanks, fighter jets, Navy ships, missiles, drones and other defense technologies.