Ralph Vince is a quantitative finance practitioner, author, and cryptographer with more than four decades of work on position sizing, leverage, drawdown control, and portfolio construction. He is the originator of the optimal-f framework and the Leverage Space Portfolio Model, published across six trading titles (five with Wiley) and a body of peer-reviewed papers. His allocation algorithms were licensed by Dow Jones Indexes (2010-2013); he served as Commodity Trading Room Team Lead and Index Constructor at the Abu Dhabi Investment Authority (1997-2000); he has consulted for dozens of hedge funds, commodity trading advisors, and money managers since the 1980s, and is a regular guest expert commentator on CNBC Arabia. Since 2023 he has architected a quantum-resistant digital-asset custody system, with published post-quantum cryptographic schemes and pending US and European patents. He is available as an expert in matters involving trading losses, leverage and suitability, risk-management practice, trading-system design, index methodology, and cryptocurrency custody and exchange mechanics, in US litigation, FINRA arbitration, and international arbitration, in English or French.