A closely-watched gauge of China's copper market has risen to the highest in more than a year, reaching $100, as a tax crackdown in the metal's biggest market spurs a shortage of scrap and boosts demand for imports.

The key China copper benchmark surged past the $100 level, reflecting tightening supply conditions following Beijing's revised value-added tax policies on recycled metals. The policy shift has disrupted the domestic scrap supply chain, forcing buyers to seek alternative sources.

Market participants note the tax crackdown has created a structural deficit in readily available copper units, particularly high-grade scrap that feeds the country's massive refining sector. This scarcity has amplified import appetite for refined copper and concentrate.

Analysts suggest the rally may persist while the China market adjusts to the new regulatory framework, with the $100 level serving as a critical psychological and technical threshold for the copper gauge.