Copper premiums in other global regions were unchanged amid lackluster spot activity.
Big trading houses have been buying SX-EW cathode in the Shanghai market for possible delivery against London Metal Exchange warehouses.
A positive LME forward spread continues to support copper premiums in Europe and the United States despite scant spot trading.
Shanghai premium narrows on low bonded stocks, tighter supply of SX-EW cargoes
In China, the cif Shanghai copper cathode premium narrowed this week on low levels of bonded stocks and tighter supply of SX-EW cathode.
Fastmarkets assessed the copper grade A cathode premium, cif Shanghai, at $55-68 per tonne on Tuesday, tightening from $53-69 per tonne a week earlier.
Shanghai-bonded copper stocks are at their lowest since November 2018, totaling 391,000-395,000 tonnes on Monday, according to Fastmarkets data. Stocks fell by 5.8% since July 15 and are down by 10.3% from July 1.