European stocks experienced a slight decline on Wednesday as investors remained cautious ahead of the Federal Reserve's policy announcement, which tempered risk-taking across regional markets. The STOXX 50 decreased by 0.3%, while the STOXX 600 remained relatively stable, indicating widespread uncertainty as traders awaited further direction regarding the US interest rate trajectory following the anticipated cut later that day. Additionally, market participants were evaluating a series of corporate updates. Aegon experienced a nearly 10% drop, a decline that positioned it at the bottom of the STOXX 600, following its announcement of plans to move its headquarters to the US and rebrand under its largest subsidiary, Transamerica. Meanwhile, Vinci fell by 3%, and Rheinmetall decreased by 2.7%, both exerting downward pressure on the index. Conversely, Siemens Energy saw a 4.2% rise, spurred by positive revenue guidance from its US counterpart, GE Vernova, which improved sentiment within the sector. Ocado continued its upward trajectory, soaring by 17%, with HSBC, Novo Nordisk, and Roche Holding recording gains of 3.3%, 3.3%, and 2.4% respectively, which helped to counterbalance the general market hesitancy.