Earlier this month, when we reported that in the latest warning about China's housing sector, the Communist Party’s People’s Daily warned that China’s regional economies need to reduce their reliance on the property market for growth and instead focus on sustainable longer-term development, we wondered if "something was afoot with China's housing sector." The story is familiar: in recent year, hundreds of cities across China have seen upswings in their local property markets under a long-term plan by Beijing to further urbanize the country. The process of building new homes and revamping old ones has only accelerated in the last few years, backed by local governments keen to boost land sales and meet red-hot property demand. Indeed, the total sales of China’s top 100 real estate developers soared 35% last year. But repeating a now familiar warning that the party is over, Beijing has once again expressed concern that some cities, looking for rapid expansion, have grown their property markets too quickly and at the expense of new industry development, adding potential froth to real estate prices. Two weeks later, our concern that something is not quite well with China's housing sector was validated by the market overnight when shares in Jiayuan International, a prominent Chinese property developer, imploded in late trading in Hong Kong on Thursday, its stock collapsing 81% due to investor unease over a sector that is staggering under vast debts just as the world’s second-biggest economy slows. According to analysts, all of whom were dumbfounded by today's move, said that the stock, which flash crashed after a chaotic day’s trading that wiped more than $3 billion from its market capitalisation with the selling promptly spilling over to many of its peers... ... was engulfed by concern that Jiayuan would default on a $350 million bond that matures this week. As we reported earlier this morning, the panic liquidation over Jiayuan also ensnared rival property company Sunshine 100 China Holdings, whose shares plunged 65% moments after Jiayuan's collapse when traders realized that the two companies share a director. "Some of these companies might have cross-shareholdings in each other and when one of those starts to tumble, it brings down other related stocks," said Bocom strategist Hao Hong. "It’s likely more similar stock crashes could happen this year. A lot of share pledges in Hong Kong are underwater, and as soon as the positions are liquidated it triggers an avalanche." The property development sector has become especially vulnerable to sharp selloffs as it has accumulated large amounts of dollar debt, while the flagging Chinese economy has boosted fears about future prospects for China's housing sector in what may end up being the country's first hard landing in decades. But the biggest problem is the upcoming debt cliff, which will force the sector to refinance at the worst possible time: according to the Financial Times, Chinese developers have about $55 billion of maturing onshore debt in 2019, which as discussed this morning accentuates concern over potential defaults. The sector is under pressure because of "potential concern over bond defaults, as [the companies] have offshore funding coming due," said Morningstar analyst Phillip Zhong. As a result "the cost of refinancing is quite expensive.” In hopes of reversing the market panic, the company published a statement on its website after the Hong Kong stock market closed on Thursday, in which Jiayuan said that it had repaid the $350 million bond, adding that "its current financial situation is healthy and business operations is normal." Clearly the market did not agree, although what exactly caused the stock to lose 80% of its value in one day remains a mystery, because while traders blamed everything from massive leverage, to stock pledges, to some variation of cross-asset holdings and interlinked collateral for the latest flash crash, the reality is that nobody really knows what happened as Castor Pang, head of research at Core Pacific-Yamaichi confirmed: "No one really knows what’s going on here. For common investors, it’s a very surprising and tough situation as there was no time to get out." * * * The bigger problem, beside the "avalanche" of overnight Hong Kong flash crashes is that after a boom in recent years, China’s property market is cooling, with developers forced to announce sharp price to move inventory, in the process leading to public anger over a sharp drop in prevailing prices. As we reported in October, this led to homeowners protesting in the streets last year in several large cities to demand refunds after developers cut prices to stimulate sales. And then there is the issue of the $55 billion in coming property developer debt maturities which risks to blow up the local debt market as rates gradually rise. Refinancing maturing debt "has always been a concern for lower-rated companies” in the property business, and will be particularly urgent this year given the scale of the debt maturing, said Mr Zhong. Quoted by the FT, Nicole Wong, an analyst at CLSA, noted that recent stimulus measures by the central bank are “aimed at only the very big [developers]”. The silver lining is that the overnight crash in property developer shares was not enough to unsettle the wider Hong Kong market, with the benchmark Hang Seng index closing barely down. Still, traders are growing more nervous that the tipping point is near: Wee Liat Lee, head of financial group and property research in Asia at BNP Paribas, said the issue of systemic risk “is a problem . . . the Chinese economy is pretty dependent on property as a sector, in terms of investment and reliance of local government on land sales and revenue”. “But I think this is an issue the Chinese government realised a long time ago,” he added. “It’s a structural problem that takes quite a bit of time to unwind." Failing that, Beijing will just bail out the entire housing sector as it has done on so many prior occasions. The alternative is the one thing that keeps every politician in Beijing up at night: revolution.