Container ports occupy a strategic position in maritime transport networks because their performance influences cargo flow distribution, connectivity between shipping services and hinterlands, and the spatial organization of regional logistics systems. Port competitiveness is inherently dynamic: ports may experience rapid traffic growth from a small market base, while established hubs may retain substantial market shares despite slower growth. Many existing assessments emphasize individual dimensions of port performance, such as efficiency, productivity, or market position, providing limited insight into how current market presence and medium-term growth interact to shape competitive positioning. This study develops a time-series-based portfolio approach to address this issue by jointly considering market position and growth dynamics in container ports. The approach combines five-year aggregated container throughput as an indicator of relative market position with Compound Annual Growth Rate (CAGR) as a measure of medium-term growth, and integrates these indicators within the Boston Consulting Group (BCG) Growth–Share Matrix. The framework is demonstrated using harmonized throughput data for major container ports in the Middle East over the 2020–2024 period. The results reveal a strongly asymmetric regional competitive structure, characterized by a concentration of market share among established hubs and higher growth rates among ports with comparatively limited market presence.