2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/208452We will compare three types of prices, namely, rational (hedging) prices, geometric (growth rate) prices, and martingale (measure) prices. We will show that rational prices in the complete market theory are sometimes contrary to common sense. In the continuous-time case, we insist that the market model should differ between the small volatility case and the large volatility case.5 pagesPricing of SecuritiesOptimization and Control91B24, 91B28text