Despite holding positions of Professor of Investment and Professor of Corporate Finance, Glen Arnold concluded that academic life was not nearly as much fun, nor as intellectually stimulating, as making money in the markets. He now spends most of his time running an equity portfolio for clients of Henry Spain Investment Services from an office in the heart of rural Leicestershire, and serves as a director on the board of Zytronic.

For decades his main research focus explored the question, "What works in investment?", drawing on the ideas of the great investors, academic discoveries and corporate strategic analysis. While he used to teach on this subject in the City of London, he would now rather concentrate on actual investment analysis for clients' portfolios.

He is the author of the UK's bestselling investment book and 14 other books.