Wall Street is recalibrating as the FAA moves to curb flight capacity in response to the federal shutdown, now in its sixth week and marking a record 37th day on Thursday. Transportation Secretary Sean Duffy announced a 10% cut in air traffic at 40 of the nation’s busiest airports to “alleviate the pressure” on air traffic controllers who have not been paid since the shutdown began. The reductions, set to begin Friday with the affected markets announced on Thursday, are expected to ripple across the system as the year’s busiest travel season approaches. Airlines are feeling the heat this week as airways show signs of distress amid the disruptions, underscoring the fragility of the system under stress.

Markets aren’t sure what to do with the news yet. In premarket trading, Delta, Southwest, United, and JetBlue gave back some of Wednesday’s gains as investors recalibrated, with United down about 1.4% and the others slipping modestly after early strength. Airlines and industry groups are in sprint mode, trying to understand the specifics and adjust schedules. United’s Scott Kirby signaled a focus on regional routes and hub-to-hub flights, offering refunds or rebooking for customers who don’t want to fly, all while protecting long-haul and core hub connectivity. This week’s turbulence has also touched the broader logistics backdrop, with headlines of the UPS plane crash in Louisville prompting renewed attention to safety and scheduling.

The disruption comes as the FAA still directs more than 44,000 flights daily, and analysts warn thousands of flights and hundreds of thousands of seats could be affected. Cirium estimates up to 1,800 flights nationwide could be cut, and O’Hare could see meaningful reductions—about 121 Friday flights if reductions are shared across airports. FAA Administrator Bryan Bedford reiterated that the system remains “extremely safe today and tomorrow,” while leaving room to expand measures if conditions worsen. The Louisville incident added another layer of caution for carriers and regulators as they navigate the week’s tighter window.

This shutdown is putting a spotlight on unpaid air-traffic controllers, many working six days a week with overtime and mounting personal costs. The result is longer lines and delays at airports as travelers scramble for updates. If you’re flying, keep an eye on airline apps and airport social channels for real-time changes, and brace for more clarity on which routes will be affected and how carriers will navigate the next few days.