IonQ raised its annual revenue forecast on Wednesday, betting on growing demand from clients for its quantum computing platform. IonQ develops trapped-ion quantum computing systems and related networking, sensing and security technologies, offering cloud-based access to its hardware that attempts to solve complex computational problems beyond the reach of classical computers. Challenges remain for quantum computing, the biggest being that qubit, a fundamental building block similar to a bit in classical computing, is incredibly fast, but also extremely difficult to control and prone to errors.