The 2G spectrum scam involved Indian government officials undercharging mobile companies for licenses to use radio frequencies for 2G subscriptions. This resulted in an estimated loss of 1.76 trillion rupees (US$38 billion) to the exchequer. Key people involved included former Telecom Minister A. Raja, who was later arrested. Several companies like Unitech and Swan Telecom that obtained licenses went on to sell stakes at large profits. The scandal impacted stock markets and led the government to set up an investigation and replace Raja as minister.