On the first trading day of December, the STOXX 50 ended virtually unchanged at 5,669, whereas the STOXX 600 saw a slight decline, down 0.2% to 575. This cautious start to the month follows a tumultuous November that yielded only modest increases for both indices. Airbus shares experienced a significant drop of 5.7%, plummeting more than 10% intraday, after reports surfaced regarding a new quality issue affecting multiple A320-family aircraft. This issue arose shortly after Airbus declared that most of the planes previously affected by a software glitch had been modified appropriately. The defense sector faced downward pressure amid optimism for a potential Ukraine peace agreement, with firms such as Rheinmetall (-2.4%), Rolls-Royce (-1.3%), and BAE Systems (-2.1%) closing the day lower. Conversely, ASML Holding saw a 2.6% increase following Fitch's affirmation of its rating, citing the company's robust market standing. Fresnillo led the performance within the STOXX 600 with a 4.7% rise, while other mining companies also enjoyed gains, with Anglo American up 1.4% and Glencore rising 2.1%.