The top-3 silver-producing countries are Mexico, Chile and Peru. Silver has the widest application in electronics, photography and jewellery. Investors buy silver in the physical form (bullions, coins, medallions) from banks, government mints or purchase silver-backed securities on an exchange. Silver options and futures are available for trading on COMEX and eCBOT in the USA, NCDEX and MCX in India, DGCX in the UAE and TOCOM in Japan. COMEX is the foremost exchange for silver derivatives. The size of one COMEX silver futures contract is 5,000 troy ounces.