South African bond yields climbed to the highest this year and the rand weakened to a one-month low as traders digested news that finance minister Nhlanhla Nene has offered to resign.

The silence of Tesla’s board over the past two days after Elon Musk went on another Twitter tirade raises fresh questions about who has what it takes to oversee the unpredictable CEO.

A report on Thursday evening that Nigeria is playing hardball with MTN Group sent the wireless carrier’s shares tumbling more than 10% shortly after markets opened in Johannesburg on Friday.