A foreign currency trader, freshly out of jail, investigates potential financial misdeeds—along with a suspicious death—in Michael Sears’s first novel, Black Fridays.

Like your protagonist, Jason Stafford, you have an M.B.A. and you were a trader on Wall Street for many years. What prompted you to take up writing?

I actually spent eight years as an actor in New York, and when that began to lose its glow, I realized there was something else I was really interested in: Wall Street. But I was always an avid and eclectic reader, and writing was something I thought I was good at and enjoyed doing. When I left the financial world in 2005, I left knowing I wanted to try writing, and I had the financial room to explore it. I took classes at the New School and New York University, and I got involved in a writing workshop. This book came out of that workshop.

Did you set out to write about the investment business?

When I started, I didn’t know. I was thrashing around a bit and wrote another book. Then, at a cocktail party, someone working in the district attorney’s office mentioned Operation Wooden Nickel, a trading scandal involving the foreign currency markets. I decided to retell that story in fictional form, and that was the genesis of Black Fridays. I wrote a good solid first draft in about 18 months and spent about six months revising it, mostly based on suggestions from my workshop and my very good agents [Sobel Weber Associates]. They really helped me focus the story and weave in the human side.

Your book is about corruption (and worse) on Wall Street, but it’s obvious you don’t think the entire financial system is evil.

People who work on Wall Street are there to make money; they’re not altruists. But most of them resist the temptation to cheat. I wanted readers to see just how easy it is to slip. Of course, it’s not just Wall Street. You can find reprehensible people in every profession.

One of the appealing things about Jason’s character is that he’s the devoted father of an autistic son. Why is that important to his story?

When I started writing the book, I just knew that Jason’s son had some sort of difficulty, some kind of challenge. I had some personal experience of autism in my extended family, and that interested me—and thought it helped humanize Jason.

Will we read more of Jason?

I continue to find new depths to Jason’s character. There are things in his story I want to develop further, so there’s at least one more book featuring Stafford. It’s about 99% done.