Jonathan Karp’s decision to step down as CEO of Simon & Schuster to launch a new imprint, Simon Six, has led to a rare event in publishing: a full-fledged search for a successor at one of the Big Five publishers.

All of the current Big Five CEOs have been promoted from within. In late 2023, Lagardère Group tapped David Shelley to lead a combined Hachette UK/Hachette Book Group, with HBG CEO Michael Pietsch sent upstairs to serve as chairman through 2024. In late 2022, Penguin Random House quickly turned to Nihar Malaviya, then president and CEO, after Markus Dohle stepped down. Macmillan CEO Jon Yaged first joined the company in 2011 as president of the Macmillan Children’s Publishing Group and eventually succeeded Don Weisberg as CEO at the end of 2022. Brian Murray has led HarperCollins since 2008 and had long been seen as Jane Friedman’s heir apparent before he took over from her as CEO.

Karp’s accession was not nearly as smooth as the others. He was named to lead S&S following the unexpected death of Carolyn Reidy in May 2020 and immediately faced the challenge of guiding the house through the pandemic. At the time, some in publishing thought Karp’s tenure as CEO would be short. S&S parent company ViacomCBS was eager to sell, and it was likely that any acquiring company, such as PRH or HC, wouldn’t make room for Karp alongside their own CEOs. But fate intervened when the sale of S&S to PRH was blocked, and private equity company KKR beat out HC as S&S’s new owner.

Even with the sale to KKR, industry speculation centered on whether Karp would fit in with the new ownership. But he had a longtime relationship with Richard Sarnoff, a publishing veteran and KKR’s chairman of media, entertainment, and education. And Karp was eager to expand S&S after years of having his ambitions thwarted by ViacomCBS.

Karp, better known for his love of books than his love of spreadsheets, had indeed turned in strong financial results. In 2022, S&S’s last year full year as part of ViacomCBS (renamed Paramount Global), revenue topped $1 billion—the first time S&S crossed that threshold as a standalone trade publisher. (Previously, S&S owned professional and educational publishing companies, and had total annual revenue of more than $2 billion.)

With KKR’s acquisition completed in late 2023, Karp embarked on an aggressive makeover of S&S—one that included bringing in new people and making good on KKR’s promise to grow internationally. The house’s first two major acquisitions were Veen Bosch & Keuning, the largest book publisher in the Netherlands, and Australian indie Affirm Press. In another international move, Karp tapped Perminder Mann, CEO of Bonnier Books, to succeed longtime S&S UK head Ian Chapman.

On the home front, Karp appointed Marysue Rucci to succeed Nan Graham as publisher of Scribner, replaced himself as publisher of the S&S flagship imprint with former journalist Sean Manning, and relaunched the Summit Books imprint under Judy Clain. Following those initiatives, the company launched the bilingual imprint Primero Sueño Press and opened a new audio-first imprint, Simon Maverick.

Karp told PW his goal was to remain CEO for five years—enough time to give him a chance to make his mark. His late August announcement has unleashed the first real publishing CEO guessing game in years, which has only been amplified by the news that KKR has appointed a search firm to help find a replacement. That led to more speculation about why KKR took the step, with opinions including that the firm could be looking for someone outside of publishing or that it was seeking a method to get sign-off on the new hire. The search firm appointment, others noted, almost certainly means S&S’s next CEO won’t come from its ranks.

Whoever gets the job, one industry insider noted, will need a combination of creativity, entrepreneurship, and positivity—the same traits Karp possessed in spades.