The advancements in early stratification and timely evaluation of therapeutic effects have revolutionized the ability to assess curative outcomes promptly. The separation between diagnosis/treatment and timely assessment of treatment response, along with delays in evaluating therapy efficacy, are significant contributors to treatment failures. Traditional approaches for evaluating curative effects face challenges posed by tumor heterogeneity and resistance, making it challenging to determine the effectiveness of a given therapeutic regimen at an early stage in clinical practice. However, molecular imaging using activatable probes has overcome these obstacles and transformed the field by shifting focus towards developing functional probes for visualizing tumors as well as enabling early stratification or timely evaluation of therapy effects. In this article, we emphasize the importance of diverse activatable molecular imaging probes and provide insights into early stratification or timely evaluation of various therapies' effects. Finally, we discuss the challenges faced in this field and propose future research directions.