The Teheran Stock Exchange's index has plummeted to its lowest level in the the past five years. The official Web site of the market reports that the index fell to 8,974, dropping below the symbolic 9,000 level for the first time since 2003. The index has fallen 18 percent since October when it was at 11,000. Sunday media reports attributed the drop to the falling prices of commodities. Most of the companies listed on the exchange are producers of steel, copper and chemicals. The Teheran Stock Exchange, which has a $50 billion market cap, was not directly affected by international financial meltdown, mostly due to isolation of Iran's financial market.