BEIJING (Reuters) – As 9 pm approaches every weekday night in China, a small army of individual investors from around the country log onto trading apps on their mobile phones and laptops. Wall Street may be about to open but these night owls are interested in trading something much closer to home – the new Shanghai crude oil futures contracts <0#ISC:> that were launched in late March. Armed with risky loans from online firms or digging into their own savings, they threaten to play an outsized role in the new market, which has got off to a roaring start. It is not for the fainthearted – one contract of 1,000 barrels costs about 476,000 yuan ($75,160) and traders are required to place a deposit – as much as 500,000 yuan – before they are allowed to trade. On average, volume between 9 pm and midnight accounts for almost 60 percent of daily turnover, equivalent to about 22 million barrels of oil worth more than 10 billion yuan. And executives of online lending platforms, managers at major brokerages, and traders interviewed by Reuters all said that most of the orders in that period come from retail investors – and a lot of it involves borrowed money. Their dominance is a reflection of the interest among China’s burgeoning middle class for investments in the country’s vast commodities market – many of the crude oil traders also dabble in other commodities such as iron ore and steel. This is especially the case after the authorities in recent years succeeded in damping down speculative activity in stocks and in real estate. It is also a sign of the kind of mania that is high-risk not only for the individual investors – who can quickly lose a lot of money borrowed on margin – but also for the long-term prospects of China’s oil futures market. The retail investors can exaggerate price swings – they tend to close out positions every day, for example, to avoid holding costs – and the market could lose liquidity quickly if a sell-off prompts a sudden outflow of their money. Liquidity, measured by open interest, hit 15,000 lots, equivalent to 15 million barrels, last Thursday, a record and almost double levels at the start of May after Washington withdrew from the Iran nuclear deal and renewed sanctions on the oil exporter. That does suggest a pick up in interest from institutional investors in recent days.