Evergrande's debt crisis has jolted the stock market. Here's why everyone's suddenly worrying about China's 2nd-largest property developer.

• The rapid growth of Evergrande in the past decade has been fueled by an unsustainable debt burden of more than $300 billion.
• Now China's second-largest property developer is showing signs of financial distress and may not be able to make upcoming interest payments.
• Here's everything you need to know about the indebted property developer that is sending shockwaves across global markets.
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If you've ever seen a picture of a massive city in China with soaring skyscrapers and apartment buildings that were virtually empty, there's a good chance those buildings were constructed by Evergrande.

China's second largest property developer has helped fuel a decades-long boom in the Chinese real estate market since its founding in 1996, which in turn has helped fuel China's growing economy.

But much of that growth has been fueled by an unsustainable surge in debt, and fears of a looming default by Evergrande sent global markets tumbling on Monday, with the S&P 500 down as much as 2.4% and the Dow Jones at one point down more than 800 points. Meanwhile, bitcoin and ether dropped more than 5% as risk-off sentiment spread to crypto.

Evergrande has more than $305 billion in liabilities, making it the most indebted company in the world. That debt has helped buy the company more than 1,300 real estate projects in over 280 Chinese cities. The company employs 200,000 employees, and its massive construction projects indirectly creates more than 3.8 million jobs per year, its website said.

But after decades of growth, mostly in speculative real estate assets that have low occupancy rates and are sometimes not even fully completed, the bill is coming due.

The company has failed to pay many of its suppliers, and to help stave off the inevitable, Evergrande incentivized many of its employees to invest in the company in exchange for their annual bonuses. The company indicated twice over the past week that it may be unable to meet an upcoming interest payment due later this week and that it could default on its debts.

The deteriorating financial condition of Evergrande has led to its stock falling nearly 80% year-to-date, and its bonds traded at historic lows in the wake of Evergrande's revelation of potential insolvency.

The writing about Evergrande's potential debt crisis has been on the wall for years. In 2012, former short-seller Andrew Left wrote a 57-page report that alleged Evergrande used shady accounting practices to mask that it was on the verge of insolvency. Left was ultimately issued a five-year ban in trading Hong Kong securities by regulators due to his report.

Bank of America said in a July 23 note that, "Evergrande ... has been hit with a number of bad headlines in the past couple of weeks, including the refusal of banks to offer mortgages to potential buyers of its properties. Its bonds have slumped into the mid-50s on price, implying a strong likelihood of a restructuring."

Given that the slow drip of bad news from Evergrande was already on the market's radar, it may be perplexing to some investors as to why stocks are selling off now.

That's likely due to the heightened uncertainty as to whether Evergrande's debt crisis represents the first domino to fall in a potentially systemic contagion that leads to more busted property developers, unpaid suppliers, and financially ruined lenders and investors, similar to the US housing crash that sparked the Great Recession of 2008.

While some analysts don't believe the Evergrande debt crisis will be China's "Lehman Brothers moment," others have speculated that Xi Jinping's government will step in to aid the company and prevent its default.

But as Andrew Left told Institutional Investor last month, that may not happen.

"I don't know what happened, but finally this past week, or month, he ran out of friends who are going to refinance his debt, and the debt became way too much," Left said of Evergrande's Chairman Hui Ka Yan. "In China, the big talk is, 'he's not too big to fail."