European stocks experienced a shift in momentum on Thursday. Initially, the STOXX 50 and STOXX 600 indices saw gains, rising by up to 1% earlier in the trading session. By afternoon, however, both indices had dipped approximately 0.2%. This change came after the brief optimism spurred by a US Court of International Trade decision. The court ruled that former President Donald Trump had exceeded his authority in implementing reciprocal tariffs and instructed the cessation of their collection. Investors' sentiments dampened as they contemplated the potential for the administration to explore alternative legal avenues to sustain its trade policies. Additionally, attention returned to the broader US economic outlook, particularly in light of recent lackluster economic data releases. Among individual stocks, Auto Trader was the most significant underperformer, dropping roughly 11% following an announcement of annual revenue falling short of expectations. Thyssenkrupp also faced a decline of 5.6%, while Novo Nordisk and Siemens each saw their shares fall by about 2%.