So far this year, the rupee has weakened 7%, while foreign investors have sold $410.30 million and $5.62 billion in equity and debt markets, respectively. Photo: Mint Mumbai:The Indian rupee on Wednesday was trading marginally higher against the US dollar, tracking gains in local equity markets. At 9.12am, the rupee was trading at 68.64 a dollar, up 0.05% from its …