Nexa Resources S.A. (NEXA) shares ended the last trading session 6.2% higher at $9.4. The jump came on an impressive volume with a higher-than-average number of shares changing hands in the session. This compares to the stock's 31.1% gain over the past four weeks.The shares of Nexa Resources gained since the company announced that it has completed the previously disclosed sale of its Otavi Project in Namibia to Midnab Resources (Pty) Ltd., a wholly owned subsidiary of Midas Minerals Ltd. The Otavi project w ...