The assessment is "likely_true" because the core claims of the statement are substantially supported by high-authority sources, despite a likely inaccuracy in the specific percentage cited. Multiple high-authority sources, including The Guardian and syndicated reports on MSN, consistently confirm that the price of copper reached a "record high." This part of the statement is strongly corroborated. The second part of the statement, a "9% increase within a specific month," is less certain and appears to be a conflation of different statistics. One Guardian report states the price surged by 10%, which is very close to 9%. However, a more detailed report from the same authoritative source explicitly clarifies that a "9% increase" figure mentioned in the same context referred to quarterly copper production, not its price. Other sources show the "9% increase" figure in completely unrelated contexts (e.g., airport passenger growth), highlighting how such numbers can be easily misattributed. Therefore, while the specific figure of 9% for the price increase is likely incorrect, the fundamental event—that copper prices surged significantly to a record high within a specific period—is well-established. The statement is mostly accurate in its substance, with only a minor, albeit specific, factual error.