Johnson has been covering the financial markets since 1996, focusing on the inner workings of the trading floors and the underside of Wall Street. He has also written extensively on technology stocks, Year 2000 and Internet stock trading.

A veteran magazine writer, Johnson has been published in George, Outside, People, Rolling Stone, Sports Illustrated, The Village Voice and Wired. Previously, he was a senior editor at Time Warner's Vibe magazine. In 1993 he executed the successful launch of Harris Publications' Slam: The In-Your-Face Basketball Magazine, where he served as founder and editor-in-chief.

Johnson's work as a writer and editor has attracted frequent National Magazine Award nominations. In 1993, his story Free Fallin' was chosen as one of 25 stories for Houghton Mifflin's collection of The Best American Sports Writing.