Altius recorded 313 priced readings of nonstop business-class round trips from Boston (BOS) to Seoul (ICN) booked 30 days out, across 138 departure dates between 2026-05-20 and 2026-10-04. Observed fares ran from US$6,851 to US$18,554. The lowest fare Altius scored on this window was US$6,851 for a 2026-07-06 departure, seen on 2026-06-06 — DECENT at the time, 12.7% below the US$7,848 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.