What 6 Citadel Securities leaders are reading (or listening to) this summer

• A recent newsletter from Citadel Securities included six executives’ beach recommendations.

• Their suggestions get philosophical, ranging from historical deep-dives to the journey of the cell.

• Here’s their chosen media, which includes books, a podcast, and even a YouTube series.

For some Citadel Securities leaders, fun in the sun means getting philosophical.

A recent newsletter from Ken Griffin‘s trading firm, which is behind nearly a quarter of all US stock trades, included six executives’ beach reads and listens. Their recommendations appeal to a range of potential beachgoers, including everything from diet advice to a 1927 classic to a YouTube series that explains egg freezing.

Here are six Citadel Securities executives’ summer media recommendations.

Matt Culek, the chief operating officer, recommended the book by Wall Street Journal reporter Keach Hagey to anyone who thinks that AI will transform business and daily life — so, basically, everyone. He called it a “compelling account of OpenAI’s founding, Altman’s leadership, and the fierce competition among leading AI firms.”

The book, published in May, tracks OpenAI CEO Sam Altman‘s journey from his childhood in St. Louis, his time at startups, his temporary ouster at OpenAI, and his current leadership. It’s based on more than 200 interviews and has 3.97 stars on Goodreads.

Chief Technology Officer Josh Woods said that the 2015 book is “as informative as it is visually stunning.” Written by the writer and lecturer Jack Challoner, “The Cell” chronicles scientific breakthroughs around life’s basic unit, tracking the evolutionary journey from single- to multi-celled organisms. On Goodreads, the book has 4.37 stars.

Shyam Rajan, the global head of fixed income, suggested Austrian writer Stefan Zweig’s 1927 classic, which was originally published in German. According to Rajan, the book “thoughtfully captures the catalysts that changed the trajectory of history ranging from the fall of Constantinople to the discovery of the Pacific Ocean.”

Other vignettes include an affair between a 74-year-old and a 19-year-old, and the story of a man who legally owned a good portion of California. The book has a 4.24 rating on Goodreads.

It seems like the summer of health for Alex DiLeonardo, the company’s chief people officer, who recommended the “eye opening” book about how to prevent chronic illness through nutrition.