We document that 20% of Compustat firms have above-median investment rates despite having below-median marginal product of capital (MPK), seemingly "misallocating" productive resources. These firms are typically younger and significantly more likely to experience a substantial upward jump in their sales and MPK in the following years. They account for a significant share of innovative activity and their investments predict future aggregate productivity in the economy, creating value in ways not captured by their MPK. We propose and estimate a simple endogenous firm growth model that captures the key features of the cross-section of firms and allows for counterfactual analysis. Hypothetical firm investment policies that ignore the potential for future jumps reduce MPK and investment dispersion but also lower aggregate productivity.