Aluminum stocks at Japan ports dip again in July - what's behind the shift?

As of July 2025, Marubeni Corp., a leading Japanese general trading house, reported that aluminum inventories across Japan's three key ports, Yokohama, Nagoya and Osaka, declined by 0.4 per cent to 315,400 tonnes.

The cause behind the sudden shift

The demand front

According to data from the Japan Aluminum Association (JAA), Janpan's aluminum demand reached 895,100 tonnes in the first quarter of 2025, up by 1.4 per cent year-on-year. Domestic consumption rose by 1.3 per cent to nearly 860,000 tonnes, while exports recorded a more substantial gain of 4.6 per cent to 35,300 tonnes.

The transportation sector was the primary growth driver, with demand rising 3 per cent to 393,400 tonnes, representing almost 45 per cent of total consumption. The food sector also posted solid growth, up 5 per cent to 97,400 tonnes.

In contrast, the building and construction sector, the second-largest end-use segment, saw demand decline by 3.3 per cent to 87,500 tonnes, weighed down by a slowdown in new housing starts and weaker demand for housing-related aluminum products.

The import front

In the first five months of 2025, Japan's total imports of aluminum and its products stood at 1.15 million tonnes. If compared with the same time frame in 2024, the import stood at 1.08 million tonnes, showing a rise of 6.43 per cent. This indicates that the country increased its imports but owing to much higher demand from various sectors, the overall inventory stood slightly lower.

The PMI front

In July 2025, Japan's final Services PMI, as reported by Jibun Bank, rose to 53.6, up from 51.7 in June and slightly exceeding the flash estimate of 53.5. This represents the fastest pace of expansion in the services sector in five months, mainly driven by strong domestic demand and the most rapid growth in new domestic business orders seen in three months.

However, export orders fell in the first dip since December and at the fastest rate in over three years, partly attributed to tourism weakness amid earthquake concerns. Employment in services plateaued, ending a 21-month streak of job growth due to labour shortages and budget constraints.

Meanwhile, inflationary pressures eased, with input cost inflation at a 17-month low and output price increases at their slowest in nine months. The composite PMI blending manufacturing and services edged up slightly to 51.6, the strongest reading since February, underscoring the role of services as the primary growth engine amid a manufacturing contraction.

Month-on-month stock movement

As of July 2025, aluminum inventories across Japan's three key ports totalled 315,400 tonnes, marking a 0.4 per cent decline from 316,700 tonnes in June 2025. In comparison, June 2025 inventories had registered a sharper month-on-month drop of 4.3 per cent from 331,000 tonnes recorded in May 2025.

In July 2025, aluminum inventories at Yokohama stood at 136,900 tonnes, down 0.87 per cent from 138,100 tonnes in June. Nagoya recorded 159,700 tonnes in July, reflecting a 1.62 per cent month-on-month decline from 162,300 tonnes in the previous month. Conversely, Osaka reported a stock increase to 18,800 tonnes in July, up 13.29 per cent from 16,300 tonnes in June. While Yokohama and Nagoya registered marginal declines, the notable uptick in Osaka's inventory partially offset the overall contraction in Japan's port stocks.

Year-on-year stock movement

As of July 2025, aluminum inventories across Japan's three major ports stood at 299,600 tonnes, reflecting a 5.27 per cent year-on-year increase. In June 2025, stocks were recorded at 317,860 tonnes, marking a 0.36 per cent decline compared to the same month in 2024. By contrast, in May 2025, inventories reached 308,700 tonnes, representing a 7.22 per cent rise year-on-year.

The July increase indicates a rebound in port stocks despite June's marginal annual drop, suggesting intermittent shifts in domestic demand and import flows. The trend underscores a dynamic supply environment, potentially influenced by fluctuating trade volumes and inventory management strategies among Japanese aluminum importers.

As of July 2025, aluminum inventories at Yokohama stood at 136,900 tonnes, down 1.24 per cent from 138,600 tonnes in July 2024. Nagoya recorded 159,700 tonnes, reflecting an 11.27 per cent year-on-year drop from 141,700 tonnes a year earlier. Osaka's stock reached 18,800 tonnes, 2.66 per cent lower than the 19,300 tonnes registered in the same month of the previous year.

The sharp contraction in Nagoya's inventories drove the overall year-on-year decline across the three ports, indicating possible regional demand surges or supply realignments. Meanwhile, the smaller drops in Yokohama and Osaka suggest comparatively stable market activity in these hubs.

Concluding statement

Japan's aluminum inventory trends in mid-2025 point to a delicate balance between supply and demand, with steady declines despite higher import volumes. The fluctuations across ports and mixed year-on-year results reflect a market influenced by shifting trade patterns, dynamic domestic consumption and evolving economic conditions. Going forward, inventory movements will likely hinge on global demand flows, import strategies and Japan's broader economic performance.