BEIJING -- Data released Monday showed the Chinese economy growing at an uncomfortably fast clip, as the nation's trade surplus hit a record high.

Trading was relatively calm by the standards of the volatile past few weeks, however. The Hang Seng Index inched downward, losing 0.1% to close at 15,621. The Shanghai Composite Index managed a gain of 0.1% to 1553.

On Friday in New York, most Chinese shares were in the green.

Netease

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climbed 1.4% to $20.70;

Kongzhong

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gained 1.5% to $11.22; and

eLong

(LONG)

added 2.9% to $13.90.

Monday, economists parsed a slew of new macroeconomic numbers and engaged in some head-scratching about whether China's economic growth is galloping out of control. Some indicators seem to say yes, and the likelihood of further administrative or monetary tightening seems to be rising.

The official trade surplus in May checked in at $13 billion, a record monthly high and well above economists' consensus expectation for $12 billion. Exports were up 25% year on year.

Also, lending in China surged last month. Local press reported bank-loan growth in May was nearly double the levels of last year, at $26.1 billion.

This follows on last week's news reports that the money supply swelled nearly 20% year on year in May.

Unlike the U.S., where economic data is released through predictable channels on scheduled dates, key statistics in China occasionally trickle out via the government press. It's noteworthy that such data leaks have been more frequent over the past few months, says Standard Chartered economist Stephen Green. That could mean official releases are being held up as bureaucrats try to figure out how to respond to the unexpected strength in the numbers, which have occurred despite an interest rate hike in April and government attempts to slow the pace of lending.

Beijing certainly doesn't want to rain on China's economic party, but nor does it want to allow unsustainable growth. Considering the growth of M2 and loans, "a lot of hot money flowed into China in May and the PBOC

People's Bank of China was unable to prevent some of it from swelling the money supply," concludes ING economist Tim Condon.

On a calmer note, the consumer price index, a key measure of inflation, remained relatively low in May, up 1.4% year on year.

Still, assuming the leaked press figures are correct, "this is all likely to create much discomfort for the PBOC -- and is going to cause some nail-biting among economists," writes Standard Chartered's Green on Monday. Until loan growth slows, the money supply will continue to surge, he says. "Data like this triggers worries of real 'overheating' -- or rather, overstimulation of the economy."

Leading economists now speculate if June macro numbers show the same hypercharged growth trends, Chinese policymakers will need to throw on some ice -- whether that takes the form of another interest rate hike, a rise in the required reserve ratio for banks or, gasp, even the appreciation of the Chinese currency, the yuan.

Monday also brought news from the banking sector, as the Hong Kong-listed Bank of Communications, among the top five banks in China, owned up to having uncovered an embarrassing $25 million yuan fraud case at a northeastern branch.

Just last week another major bank, Shanghai Pudong Development Bank, said collateral for $16 million in mortgage loans had been faked.

Over the past few years, banks have become more open about mismanagement and fraud within their ranks, even if their actual operations remain far from transparent. "This could be viewed as progress," says Beijing-based Fitch Ratings analyst Lydia Lin. "But in another sense it still shows that Chinese banks have much more to do in improving internal controls. There are many branches still operating as minibanks" away from headquarters, she explains.