Key Takeaways Comfort Systems expanded its gross margin by 340 bps to 23.6% in the first nine months of 2025.The backlog surged 65% year over year to $9.38B, led by technology and advanced manufacturing work.FIX benefits from selective bidding, labor discipline and a higher-margin project mix entering 2026.Comfort Systems USA (FIX) has been witnessing gross margin growth since the start of 2025. For the first nine months of 2025, its gross margin expanded year over year by 340 basis points (bps) to 23.6%, w ...