How James Inglis-Jones and Samantha Gleave turn a disciplined process into exceptional execution
Adapted from Stock Market Maestros: The winning habits, strategies, and mindsets of the world’s best investors, which will be published by Harriman House in March 2026 (Preorder now).
By Lee Freeman-Shor and Clare Flynn Levy
Lee Freeman-Shor is the author of the international bestseller, The Art of Execution: How the world’s best investors get it wrong and still make millions, named by Investing By The Books as one of the “Top 20 Investment Books Ever.” Before becoming a writer, the Citywire 1000 report recognized Lee as one of the world’s top fund managers. His flagship fund received a Gold rating from S&P Capital IQ and the top (AAA) rating by Citywire.
Clare Flynn Levy is CEO & Founder of Essentia Analytics. Prior to setting up Essentia, she spent ten years as a fund manager, in both active equity (running over $1B of pension funds for Deutsche Asset Management), and hedge (as founder and CIO of Avocet Capital Management, a specialist tech fund manager).
When you meet James Inglis-Jones and Samantha Gleave, it is tempting to focus on the contrast. He is the 6-foot-5 former Oxford rower you might spot skimming across the water on a hydrofoil; she is the Glasgow-born naval reservist who grew up sailing on the west coast of Scotland. Today, they co-manage over a billion dollars in European long and long-short strategies for Liontrust plc. Their partnership is grounded not in similarity, but in a shared conviction: that a disciplined, evidence-based process is the antidote to the emotions that derail even the most highly-skilled investors.
In Stock Market Maestros, we profile twelve investors who don’t just pick good stocks, they also know how to run their winners and cut their losers before they spiral out of control. Pre-order now.
James did not begin his career with that view. Early on, he assumed that great investors succeeded through innate talent.
That changed when he started to work with a successful portfolio manager who showed him that success in investing can be achieved by adopting a systematic approach that exploits flaws in investor behavior. This was an approach that James helped further develop into a process around one foundational idea: company cash flows signal where to invest, and what to avoid (or short).
While that approach worked most of the time, during the 2008 crisis he watched his then co-PM make instinctive but crucial calls that the process would have picked up too late.
When his co-PM retired, James knew that he lacked the same intuition, particularly around shifts in market regime – so he went about looking for ways to systematize it.
Enter Sam. She joined James in 2012 and spearheaded the effort to systematize an experienced investor’s intuition at market turning points. The net result was a series of secondary scores – signals – designed to help them know when to lean in and when to avoid (or short) certain companies. They had uncovered objective signals that indicated when changes were afoot.
This has resulted in some impressive decisions. During the COVID crash of 2020, their “regime indicator” signaled extreme investor anxiety, a backdrop in which deeply contrarian value stocks have historically outperformed. Even as fear dominated the market, the evidence told them to act and lean into stocks with high contrarian value secondary scores. They bought stocks that were uncrowded and trading at distressed valuations, including Bank of Ireland, which went on to produce a fivefold return.
As those names recovered, James and Sam’s secondary scores told them to keep riding the positions long after the initial value thesis had played out, as they captured the transition to momentum as a supporting factor, thus preventing them selling too early.
Essentia’s Behavioral Alpha analysis captures the effect of that approach. Over recent years, James and Sam have delivered a Behavioral Alpha Score of 63.3, reflecting consistently skilled decision-making across stock picking, timing and sizing. Their hit rate, at 49 percent, is not unusual among top investors; even the best often make more wrong calls than right ones. What matters is the asymmetry of outcomes. With a payoff ratio of 246 percent, their average winner has added nearly two and a half times as much value as the average loser has destroyed. It is this ability to let winners run and cut losers early — rather than a high batting average — that marks a defining pattern Essentia sees in top performers.
Their chapter in Stock Market Maestros goes deep into the machinery behind those numbers, from how they identify companies to buy or short from a cash flow perspective, and how they use secondary scores to help know when to sell a winner and a loser. Through real-life case studies, they walk through the decisions that shaped their track record, illuminating not just what they did, but why.
If you want to understand how these two investors with complementary strengths became Maestros of execution, pre-order your copy of Stock Market Maestros: The Winning Habits, Strategies, and Mindsets of the World’s Best Investors today.
Stock Market Maestros: The winning habits, strategies, and mindsets of the world’s best investors is published by Harriman House and goes on sale in March 2026. Reserve your copy now!
About Essentia Analytics
Essentia Analytics is the leading provider of behavioral data analytics services to professional investors and allocators of capital. Led by a team of experts in investment management, technology and behavioral science, Essentia combines next-generation decision attribution analytics technology with human coaching to help both equity fund managers and allocators identify investment skill and bias — and capture performance that was previously being lost to decision-making deficiencies.
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