(Bloomberg) —If an episode of Game of Thrones seems to go too quickly, consider the lifespan of a ferrosilicon contract on China’s Zhengzhou Commodity Exchange.

Trading in futures of the alloy used to harden steel exploded this week, with the average contract on Wednesday held for an estimated 39 minutes. By comparison, the tenure of crude oil contracts on the New York Mercantile Exchange was about 47 hours.

Ferrosilicon is just the latest commodity contract pounced on by China’s hordes of speculators with an intensity that makes the world’s most liquid markets look leisurely. In repeated bouts of manic trading over the past year, they’ve piled in and out of everything from cotton to zinc, eventually prompting regulators to step in and calm the frenzy.

“There are large volumes of short-term investment in steel and related products such as rebar, iron ore and ferroalloy futures with investors trading momentum and sentiment,” Wei Lai, an analyst at COFCO Futures in Shanghai, said by phone.

Trading in ferrosilicon peaked on Wednesday with more than 705,000 contracts changing hands. Prices surged to a record $7,726 yuan a metric ton the previous day, up 25 percent this month. Up until August, it was one of the quieter contracts on the exchange, with 22,000 contracts trading daily on average in July.

A spokeswoman for the exchange declined to comment on market movements.

Trading in steel and iron ore is the heaviest on China’s three commodity bourses, with volumes that dwarf contracts such as ferrosilicon. An average 7.9 million steel reinforcement bar futures traded on the Shanghai Commodity Exchange in July. Earlier this month, the bourse hiked fees to calm trade in rebar after prices ran up to the highest in four years on speculation that China’s supply-side reforms are creating a shortage.

Analysis of aggregate open interest, volumes and trading hours illustrates the extraordinary pace at which Chinese investors are trading commodities futures.

Dividing the average aggregate open interest at the end of each day by the aggregate volume shows the number of futures traded for every outstanding contract. Multiply that ratio by the number of hours in each trading day and you get an estimate for the average tenure of each contract.

While Wednesday’s ferrosilicon contracts were held for less than an hour, the average for the month is 3.6 hours. Futures in Siliconmanganese, another alloy used in steel production, change hands at the fastest pace, with an average tenure in August of 2.7 hours. Iron ore is about 3.8 hours on average and rebar is 4.3 hours.