I'm one of the authors of "Mastering Bitcoin, 3rd ed" and I'm donating all of my royalties to Brink Technologies, a 501(c)(3) charity that supports Bitcoin developers.

• The answer will be settled using this record of all of my royalties and donations (updated monthly): https://docs.google.com/spreadsheets/d/1sclXwm86JE2rpTfymZz9yqysRHZ0JEpemEL3F5XZvH0/edit#gid=0

• There's a second co-author on the book. The answer to this question will not factor in any donations he makes from his royalties. It only counts royalties donated by me.

Notes:

• Physical and ebook sales began around 2023-11-15, so royalty amounts before then only include the pre-release versions on the publisher's website

• The announcement dedicating the royalties can be found here: https://dtrt.org/posts/mb3e-announcement/#on-the-brink

• A blog post with revenue statistics by another author (for a completely different book) by the same publisher may be found at the following URL. I think there's a chance that "Mastering Bitcoin, 3rd ed" could do roughly as well as the book, but as a co-author, I receive a smaller portion of the royalties than a solo author. https://martin.kleppmann.com/2020/09/29/is-book-writing-worth-it.html