In “Trillions,” journalist Robin Wigglesworth explores the history of index funds and how they’ve become integral parts of society. Wigglesworth ends the book with warnings of the dangers associated with “the greatest invention in the history of finance,” the products of financial engineering.

The first half of the book is a compilation of anecdotes and short biographies of key players, institutions and organizations from the 20th century who helped make the major index funds.

There are several must-read chapters in the book, including “Buffett’s Bet” and “Vanguard Rising.”

It’s also imperative that the last four chapters are read too. In these last four chapters, Wigglesworth highlights an alternative reality where power is saturated into the hands of the index fund kings like Fidelity National Financial Inc., Vanguard Group Inc. and BlackRock.

Books like “Trillions” are a reminder that so much of what people take for granted and view as second nature took time to invent. There were many parties involved and many hurdles to overcome.

In the chapter titled “Deal of the Century,” Wigglesworth does a deep dive into BlackRock Inc.’s accusation of Barclays PLC, under which its iShares division existed. The deal provided Barclays with enough funds to avoid bankruptcy during the 2008 financial crisis and helped them become the “informal king of Wall Street.”

A significant portion of the book is dedicated to the invention of exchange-traded funds, a product that allows individuals to trade a variety of securities on public exchanges. Although the ETF industry is now $9 trillion, Wigglesworth wrote that they “account for about a third of all trading on US exchanges.” That wasn’t always the case as ETFs struggled to gain traction in their early years.

In the chapter titled “This is Water,” the inner workings of index funds are exposed. As Wigglesworth explains, there are several matters of concern, one of them being the narrowing of funds into certain companies creates the possibilities of bubbles forming.

“Trillions” is a reminder of how far financial engineering has come and prompts readers to subjectively look at the things around them.