Since e-book sales exploded in 2009–2010, the adult fiction category has seen the steepest drop in print units of all the major book segments as readers migrated to digital formats, particularly in such fiction genres as romance, mystery, and science fiction. Since 2010, adult fiction units have declined every year, including 2014 and 2013, when units, as measured by Nielsen BookScan, fell 8% and 11%, respectively. But that trend line could be reversed in 2015 thanks in part to three huge print bestsellers: Go Set a Watchman, Grey, and The Girl on the Train.

Through Aug. 16, 2015, each of these titles has sold more than one million print units at outlets that report to BookScan, which estimates it captures 80% to 85% of all print sales. In contrast, Gone Girl, the top-selling print book through Aug. 17, 2014, sold less than half of each of these three big 2015 titles, and less than All the Light We Cannot See, the fourth bestselling print book so far in 2015.

And it’s not just the top of the fiction bestseller list that is driving the overall adult fiction gains. The 100 bestselling adult fiction titles to date in 2015 have sold more 11 million copies—compared to more than eight million copies in the same period last year. In total, unit sales of adult fiction are up 3% so far in 2015 over the similar period in 2014, helping to offset a 4% drop in unit sales in the juvenile fiction category.

Publishers don’t have one particular reason for the turnaround. An improving economy and a more stable retail environment, as well as the slowing growth of e-book sales, are some factors executives mentioned when discussing the market. Go Set a Watchman has been a particular print favorite. The novel sold more print copies in its first week than any book since Dan Brown’s The Lost Symbol was released in September 2009, and hardcover sales of Watchman are double that of e-books sales. Grey and Girl on the Train, however, have managed to sell in huge print quantities while also selling in big numbers as e-books.

One executive speculated that with e-books now discounted less than they have been in recent years, customers are more willing to pay a little more for print books. In general, publishers contacted by PW were more encouraged about the improving print sales picture than worried about softening e-book sales.

Top 5 Adult Fiction Print Bestsellers, 2015

Title Author Publisher Units sold through Aug. 16
Go Set a Watchman Harper Lee HarperCollins 1,251,880
Grey E.L.James Vintage 1,154,029
The Girl on the Train Paula Hawkins Riverhead 1,052,943
All the Light We Cannot See Anthony Doerr Simon & Schuster 698,179
To Kill a Mockingbird Harper Lee Grand Central 386,381
Total 4,543,412

Top 5 Adult Fiction Print Bestsellers, 2014

Title Author Publisher Units sold through Aug. 16
Gone Girl Gillian Flynn Broadway 438,463
The Goldfinch Donna Tartt Little, Brown 351,427
Orphan Train Christina Baker Kline William Morrow 297,701
The Invention of Wings Sue Monk Kidd Viking 266,789
Mr. Mercedes Stephen King Scribner 260,337
Total 1,614,717