Des Multiples Statiques aux Rendements Prédictifs : Le Taux de Rendement Interne des Actions (SIRR) et la Prime de Risque des Actions (SRP) comme Indicateurs Prospectifs pour l’Évaluation et la Prévision des Marchés Boursiers Mondiaux

This paper presents the Stock Internal Rate of Return (SIRR) and the Stock Risk Premium (SRP) as next-generation valuation and forecasting metrics for entire stock markets. By extending the traditional Price-to-Earnings (P/E) ratio through the Potential Payback Period (PPP) framework, these indicators express valuation in time- and yield-adjusted terms, integrating earnings growth and discount rates into a unified measure of prospective return. The SIRR represents a market's intrinsic yield, while the SRP captures the excess of this yield over the risk-free rate, adjusted under a 5% capping rule that applies only in the final SRP step. This modification preserves local monetary realism while ensuring global comparability. Empirical validation across two distinct periods — December 2023 to October 2024 and February to October 2025 — confirms the predictive strength of these metrics. Correlations between SIRR and subsequent market performance reach r = 0.76–0.82, while the capped SRP delivers similarly robust results (r = 0.79) without penalizing high-rate economies. Together, SIRR and capped SRP form a comprehensive and operational measure of market yield, enabling forward-looking global market ranking. As of October 2025, the model identifies Asia (China, Taiwan, Japan) and Germany as the most promising markets for 2026, converging toward an intrinsic yield equilibrium of 5–6%. The findings establish SIRR and SRP as groundbreaking prospective return metrics that unify valuation theory, empirical performance, and predictive capability across global equity markets.