Rocket Lab USA, Inc. (RKLB) shares tumbled 8.50% in 24-hour trading as investors reacted to a mixed second-quarter earnings report that was overshadowed by a disappointing third-quarter margin outlook and a likely delay in the debut of its Neutron rocket.

The sell-off was triggered by the company's Q3 GAAP gross margin guidance of 29% to 31%, which fell substantially below the analyst consensus of 37.6%. Management attributed the margin compression to a shift in product mix, with lower-margin satellite platforms expected to account for a larger share of revenue going forward. Adding to the pressure, Rocket Lab appeared to push back the timeline for the first flight of its Neutron rocket, now aiming to deliver the vehicle to the launch pad in the fourth quarter rather than launching it then, with CEO Peter Beck noting that the window for a year-end launch is narrowing. The company also reported a Q2 loss of $0.08 per share, missing the consensus estimate of a $0.06 to $0.07 loss.

The negative sentiment overshadowed several positive developments in the quarter, including record revenue of $234.1 million, up 62% year-over-year and beating estimates, a record backlog of $2.36 billion, and Q3 revenue guidance of $250 million to $265 million that exceeded Wall Street's expectations. Rocket Lab also announced new contract wins worth over $1 billion, a Neutron launch deal with Kepler Communications, and the establishment of Rocket Lab Germany to expand its European footprint.