The Big Five’s grip on the hardcover bestseller lists continued in 2023, as 84.8% of the 2,080 positions on PW’s weekly hardcover lists were occupied by titles published by major houses. But for the second year in a row, the Big Five’s hold on the lists loosened a bit, dropping roughly three percentage points from 2022, on the heels of a similar three-percentage-point drop that year compared to 2021.

Penguin Random House’s failed acquisition of Simon & Schuster in late 2022 didn’t prevent the nation’s largest trade publisher from increasing its hold on the hardcover bestseller lists last year, with its share of list positions rising to 36.7%, from 34.6% in 2022. Simon & Schuster (14.2% in 2023 vs. 14.3% in 2022) and Macmillan (7.7% in 2023 vs. 7.9% in 2022) had minimal declines, while HarperCollins (16% in 2023 vs. 17.5% in 2022) and Hachette Book Group (10.2% in 2023 vs. 13.7% in 2022) posted more significant drops.

The two independent publishers that did the most to chip away at the Big Five’s control of the hardcover lists were Entangled Publishing and Grove Atlantic. Entangled’s original edition of Fourth Wing by Rebecca Yarros was on the hardcover list for 33 weeks, and a special edition of the novel was on the list for six weeks, as was Yarros’s Iron Flame, which was published late in the year. Grove’s The Covenant of Water by Abraham Verghese also stayed on the list for 33 weeks.

Given changing market realities, PW is breaking out trade paperback bestseller lists from mass market lists for the first time this year in its annual analysis of bestsellers by corporation. That breakdown shows that the Big Five’s control over the trade paperback lists (61.6%) isn’t as great as its control over the hardcover lists, but with an important caveat: “entrepreneurial” publisher Sourcebooks was the top publisher of trade paperback bestsellers last year.

In all, Sourcebooks led with 29 titles on the trade paperback list, occupying 213 positions of the 1,040 positions and accounting for 20.5% of all trade paperback bestseller slots. Since the beginning of 2023, PRH has owned a 53% stake in the Naperville, Ill.–based publisher, but Sourcebooks remains “structurally and operationally” separate from PRH, sources explained, and Circana BookScan (which powers PW’s bestseller lists) continues to measure Sourcebooks’ bestseller list share separately from that of PRH. Were they combined, PRH/Sourcebooks would have controlled 36.8% of all trade paperback bestseller slots last year—approximately the same as PRH’s share of slots on the hardcover lists.

And in a further note on Sourcebooks’ 2023 trade paperback performance, 23 of its bestsellers were published by its Bloom Books imprint, which accounted for 195 trade paperback slots. Ana Huang was Bloom’s big star, placing seven titles on the PW trade paperback charts for a total of 123 weeks.

In 2023, HarperCollins and its Harlequin imprints had the largest share of mass market bestseller list positions. And while the Big Five had a hefty 83.6% share of mass market bestseller list positions, nearly all of the remaining positions on the PW mass market list were held by titles from Kensington, which racked up 40 mass market bestsellers occupying 160 positions. The indie publisher’s 15.4% share of mass market list positions placed it third in mass market bestseller dominance, trailing only HarperCollins and PRH.

Of course, mass market sales have been on a steady decline in recent years. According to Circana BookScan, the format accounted for only 3.4% of unit sales in 2023.