Shares of Rocket Lab USA, Inc. (RKLB) experienced a significant after-hours plunge of 5.05% on Thursday, following the release of the company's fourth-quarter financial results.

The space launch and systems company reported quarterly earnings that surpassed analyst expectations, with revenue of $179.7 million beating estimates and a per-share loss of $0.09 coming in narrower than the anticipated $0.10 loss. The company also posted record annual revenue growth of 38% and provided strong guidance for the first quarter of 2026.

Despite the positive financial performance, investor sentiment turned negative due to the announcement of a further delay for the company's Neutron medium-lift rocket. The first launch of the Neutron vehicle is now targeted for the fourth quarter of 2026, a postponement attributed to a recent stage 1 tank test failure. This development overshadowed the strong quarterly results, leading to the sharp decline in the stock price during after-hours trading.