SHANGHAI, Aug 1 (SMM) - The weekly average discount of high-grade NPI stood at 529 yuan/mtu against refined nickel last week, 107 yuan/mtu higher than a week earlier. In the pure nickel market, the bears paid off as the Fed raised the interest rates as expected. Therefore, the prices of pure nickel rose. The spot supply of pure nickel became relatively sufficient. During last week, the NPI prices continued to decline due to the oversupply and weak demand. It is expected that with the continuous increase of Indonesian NPI output, the oversupply will become more obvious. In the short term, the price difference between high-grade NPI and pure nickel is expected to remain high.