The completion of a significant project like building one of the first quantum computers in the UK is a major milestone for Rigetti Computing. This achievement not only showcases the company's technical capabilities and leadership in the quantum computing space but also likely boosts investor confidence in its future prospects. The positive market reaction, as indicated by the increase in stock price, reflects the significance of this development for Rigetti Computing. Investors may view this successful project completion as a sign of the company's potential for future growth and innovation, leading to increased demand for RGTI shares.