GLAS (20%) and Downing (19%) have the highest attrition rates among the fastest-growing companies, suggesting pressures from rapid expansion, shifting team dynamics, and integration challenges. Hayfin Capital Management (18%) and Schonfeld (17%) also face elevated attrition. Interestingly, while attrition among the fastest-growing firms is higher than the biggest companies, it remains below the investment banking average of 19%, indicating that retention challenges may be less severe than in the broader industry.