Futures contracts including rebar, iron ore, coking coal and coke slid after authorities stepped up efforts to crack down on speculation.

When the market closed, the price of iron ore dropped 2.96 percent. Rebar futures, a construction steel product, plunged 4.52 percent and coking coal dropped 4.34 percent, according to a report of the Wall Street Journal.

Volumes for hot-rolled steel coil plummeted 62.87 percent from more than 1.22 million on April 21 to about 456,000 on Friday, according to data from the Shanghai Futures Exchange.

"In terms of trend, the rising period of futures market has reached its peak and will embrace a one-and-a-half-month period of decline," Wu Chenhui, an independent industry analyst, told the Global Times on Tuesday.

At their peak this year, Dalian iron ore prices had risen 73 percent, and rebar in Shanghai by 62 percent.

On some days, the trading volume in iron ore futures on the Dalian exchange exceeded China's total imports for 2015, Reuters reported on Friday.

Regulation also played an important role in curbing speculation in futures market, Wu said.

On Friday, the China Securities Regulatory Commission (CSRC) reiterated it was taking greater efforts to crack down on excessive speculation and illegal activity in the futures market.

Furthermore, it vowed not to let the market be the "hot-bed" for speculators.

On April 27, the Dalian Commodity Exchange raised the minimum collateral requirements on its coke and coking coal contracts to 9 percent from 8 percent, according to a statement posted on its website. On April 28, it doubled transaction fees to 0.072 percent on the contracts.

On April 25, the Shanghai Futures Exchange boosted transaction fees for hot-rolled coil contracts from 0.004 to 0.01 percent and rebar contracts from 0.006 to 0.01 percent.

On April 26, the Zhengzhou Commodity Exchange also increased the minimum collateral requirement for thermal coal contracts from 5 percent to 6 percent.