A Chinese credit crisis would see the country's banks rack up losses 400 percent larger than the hit U.S. banks took during the subprime mortgage crisis, storied hedge fund manager Kyle Bass has warned in a letter to investors.
"Similar to the U.S. banking system in its approach to the Global Financial Crisis (GFC), China's banking system has increasingly pursued excessive leverage, regulatory arbitrage, and irresponsible risk taking," Bass, the founder of Dallas-based Hayman Capital, wrote in the letter dated Wednesday.
"Banking system losses - which could exceed 400 percent of the U.S. banking losses incurred during the subprime crisis - are starting to accelerate."
China's banking system has grown to $34.5 trillion in assets over the past 10 years, from a base of $3 trillion, wrote Bass, who is famed as one of the few major investors to correctly call the U.S. subprime housing collapse that kicked off the 2008 global financial crisis. That prescience earned him a mention in Michael Lewis' book "Boomerang," which was about the European credit crisis.
This expansion in the banking system's asset base was fueled largely by rapid credit expansion, Bass wrote, that helped fund the huge, and often inefficient, infrastructure spending program that has propped up China's growth.
"China's [banking] system is even more precarious when we realize that, even at the biggest banks, loans are not made to borrowers based on their ability to repay," he wrote. "Instead, load decisions are political decisions made by the state."
Add to this the danger posed by China's shadow banking system - made up of instruments Bass claimed the country's banks used to subvert restrictions on lending - and the upshot was there were "ticking time bombs" in China's banking system, the hedge fund manager explained.
"Chinese banks will lose approximately $3.5 trillion of equity if China's banking system loses 10 percent of assets," Bass wrote. "Historically, China has lost far in excess of 10 percent of assets during a non-performing loan cycle."
He noted that U.S. banks lost about $650 billion of their equity throughout the global financial crisis.
The letter said that the Bank for International Settlements (BIS) estimated that Chinese banking system losses from the 1998-2001 non-performing loan cycle exceeded 30 percent of gross domestic product (GDP).
"We expect losses in this cycle to exceed prior cycles. Remember, 30 percent of Chinese GDP approaches $3.6 trillion today," he warned.
Bass wrote that he expected the massive losses to force Beijing to recapitalize Chinese banks and sharply devalue .
"China will likely have to print in excess of $10 trillion worth of yuan to recapitalize its banking system," he said. "By the time the loss cycle has peaked, we believe the renminbi will have depreciated in excess of 30 percent versus the U.S. dollar."
The hedge fund manager didn't return an email sent outside office hours requesting comment on the investor letter, which the Wall Street Journal reported was the first he had sent in two years.
Bass' sentiments on the yuan aren't new, with the Wall Street Journal reporting earlier this month that he was among the money managers making bearish bets on the currency.
The dollar has already fallen about 5.9 percent against the yuan since August, when a sharp devaluation by the People's Bank of China (PBOC) roiled markets; the greenback was fetching around 6.5710 yuan on February 5, the last day of trade before China's markets closed for a week-long Lunar New Year holiday.
The PBOC has introduced a slew of measures to arrest, or at least slow, declines in the currency in the hope of achieving an orderly depreciation.
The central bank has asked banks making yuan loans abroad to set aside more in reserves and has also hoovered up yuan in Hong Kong, a key market where the bearish bets have been made, effectively making it more expensive for traders to borrow the yuan to make these trades.
China's state-owned publications have also chipped in with stinging editorials admonishing greedy speculators for betting against the currency. Prominent investor George Soros was recently likened to a "crocodile" that had declared "war" on China for suggesting while at the World Economic Forum in Davos, Switzerland, that China's economy was headed for a hard landing.
In his letter, Bass casts the attacks on Soros as confirmation of his views.
"China's public reaction in its state media to George Soros' comments in Davos was in character for a country that is on the precipice of a large devaluation," Bass said.
While many have pointed to China's large - albeit shrinking - pile of $3.23 trillion in foreign-exchange reserves as a defensive wall against a crisis, Bass says that's simply not enough.
He estimates China really only has around $2.1-2.2 trillion in reserves after adjusting for several factors including about $700 billion that could be tied up in China's sovereign wealth fund CIC. That's below his estimate of the $2.7 trillion minimum China would need to effect a banking sector bailout.
"China's liquid reserve position is already below a critical level of minimum reserve adequacy," he said.
Predictions of a Chinese economic disaster have been circulating for a long time; Gordon Chang's book "The Coming Collapse of China" was published in 2001.
However, the mainland saw economic growth slow to a 25-year low of 6.9 percent in 2015 amid its transition toward a consumption-driven economy and away from its manufacturing roots.
When it comes to positioning for his expectations of a Chinese bank implosion, Bass wrote that he was thinking broad.
"What happens in China will not stay in China," he said. "We decided to liquidate the majority of our risk assets."
He did not appear likely to buy back in to the market any time soon.
"The next 18 months will be fraught with false-starts, risk rallies, and second-guessing," he wrote.
To be sure, some of Bass' other doomsday bets haven't yet come to fruition.
For more than five years, he has called for a collapse in Japan government bonds (JGB) as part of a yet-to-materialize full-blown financial crisis there. That trade, dubbed a widow-maker, has so far backfired spectacularly.
Instead of a collapse in JGB prices, they've surged, with the benchmark 10-year seeing negative yields for the first time this week. Bond yields move inversely to prices.
Hayman Capital had returns of about 1.7 percent last year, according to a Bloomberg report.
—Neelabh Chaturvedi contributed to this article.
—By CNBC.Com's Leslie Shaffer; Follow her on Twitter