The Baltic Dry index, the benchmark for freight costs for bulk commodities such as iron ore, coal and grains, has risen by over 60 per cent since the start of the year, bolstered by surprisingly strong demand for steel.

Some analysts had thought that the sharp drop in the Baltic index in January — it hit a seven-month low on January 29 — was an early warning sign that the boom in commodity markets was about to come to an abrupt end. The fall in the Baltic index earlier this year was paralleled by weakness in base metals prices amid concerns about the impact of the slowdown in the US on the global economy.