In brief: When it comes to collectible signatures, which celebrity, living or dead, do you think currently has the most valuable? Turns out it’s Apple co-founder Steve Jobs, whose autograph is now worth around $51,000.

According to the 2018 Paul Fraser Collectibles Autograph Index, Jobs’ signature has increased in value by more than 27 percent since 2000, jumping 14.3 percent alone over the last year.

According to Daniel Wade, head writer of Palo Fraser Collectibles, part of what makes Jobs’ autograph so valuable is because he rarely signed his name. "Jobs was a reluctant signer, always maintaining that Apple was a team effort,” he said.

Jobs sits in front of renowned physicist Stephen Hawking, who sadly passed away earlier this year. His amyotrophic lateral sclerosis meant he was unable to write by around the 1970s—he used his thumbprint after that time—so a book containing his written name is worth $38,000; a 100 percent rise over the last few months.

Behind Jobs and Hawking are James Dean ($22,982), Bruce Lee ($15,321) and Marilyn Monroe ($14,044). Paul McCartney has the most valuable autograph of a living person—$3751. Others include Prince William, Prince Harry, and J.K. Rowling. President Trump’s is worth $830, which has increased 15.3 percent this last year.

Back in March, a one-page job application form filled out by Steve Jobs three years before he co-founded Apple brought $174,000 at auction. His leather jacket sold for $22,400 in 2016, while a magazine he signed went for over $50,000 last year.