If anyone has view on how the Global Coal Prices will move, he can play his bets through NMDC & GMDC. For any average Indian, who is not a High Networth Individual (HNI), this is most easiest way for proxy trading in Coal.
10 year stock price chart of NMDC & GMDC, moves in tandem with Australian Thermal coal prices. (Coal, Australian thermal coal, 12000- btu/pound, less than 1% sulfur, 14% ash, FOB Newcastle/Port Kembla, US Dollars per Metric Ton).
Both the Stock has Correlation Coefficient more than 0.80.