Altius recorded 309 priced readings of nonstop business-class round trips from Chicago (ORD) to Brussels (BRU) booked 60 days out, across 138 departure dates between 2026-05-20 and 2026-10-05. Observed fares ran from US$4,003 to US$9,599. The lowest fare Altius scored on this window was US$4,003 for a 2026-08-25 departure, seen on 2026-06-26 — STRONG at the time, 15.8% below the US$4,754 this route was typically running that day.
A fare can move between our two readings of the same day, most often on the days furthest below typical. Where a day's two readings differ enough to matter, the chart marks that day and both readings can be read separately.