The business at these exchanges stood at Rs 53.82 lakh crore in the same period of 2013-14 fiscal.
According to data released by the commodity markets regulator FMC, the trading volumes have fallen maximum in bullion, followed by energy items, industry metals and agricultural commodities.
The business from bullion fell 67.40 per cent to Rs 7.96 lakh crore during April-August 15 of the current fiscal, from Rs 24.43 lakh crore in the year-ago period.
Similarly, the turnover from energy items has dropped 65 per cent to Rs 4.87 lakh crore from Rs 13.82 lakh crore, while the business from metals fell by 51 per cent to Rs 5.01 lakh crore from Rs 10.16 lakh crore in the review period.
The business from farm items declined 15.52 per cent to Rs 4.55 lakh crore during April-August 15 of this fiscal, as against Rs 5.38 lakh crore in the same period last year.
Experts said trading volumes have been falling owing to imposition of commodity transaction cost and dent in investors' sentiment after the Rs 5,600 crore payment scam surfaced at the National Spot Exchange Ltd (NSEL).
Currently, there are ten commodity bourses in the country, of which five operate at national level.