Magic Leap Inc. is an oddity in the tech industry, even by Silicon Valley’s heady standards.

Located adjacent to a trailer park in South Florida, Magic Leap has amassed nearly $1.4 billion in funding, more than 500 employees and a dozen big-name investors.

Yet the secretive startup still lacks one major detail: a product. After nearly four years, Magic Leap still hasn’t publicly shown a head-mounted gadget it is developing that projects images onto users’ eyes so the digital world appears to interact with real life.

On Tuesday, the startup confirmed another big step toward bringing its so-called mixed-reality device to consumers, announcing it raised $794 million in new funding from some top firms in tech, finance and entertainment. Chinese Internet giant Alibaba Group Holding Ltd. led the funding round, which Magic Leap says values the Dania Beach, Fla., company at $4.5 billion.

Alphabet Inc.’s Google and Qualcomm Inc., which backed Magic Leap’s $542 million round in October 2014, reinvested. They were joined by J.P. Morgan Chase & Co., Fidelity Management and Research Co., Morgan Stanley, Wellington Management Co., funds advised by T. Rowe Price Associates Inc. and Time Warner Inc. unit Warner Bros.