An 82-year-old retiree is a regular at the China Securities office in Beijing where he monitors the rise and fall of one of the two shares he holds. Credit:iPhoto The Shanghai Stock Exchange's daily turnover exceeded that of Wall Street's New York Stock Exchange for the first time in its history last month. Price-earnings ratios (a valuation method for shares), particularly for riskier small-cap stocks, are looking stretched by conventional measures, prompting concerns over whether prices are entering bubble territory, or at the very least, whether the market's stellar bull run is sustainable. The amount borrowed by investors to purchase stocks has quadrupled from a year earlier, fuelled by a recent surge in margin trading, which, in turn, is often funded by China's infamous shadow lending sector. Investors continue to pile in at an increasing rate. Five million new trading accounts were opened in March. And, just last week, another 3.3 million new share accounts were created; 10 times more than normal.

An image that went viral of a streetside banana vendor watching the stocks. Credit:@wmiddelkoop via Twitter Many economists and demographers point to the lack of a comprehensive social welfare net in China as a key reason for its people's stereotypical streak of conservatism and a high savings rate. However, the inverse is also true, and many, especially younger Chinese, are entrepreneurial, willing to take risks, particularly when there is fast money to be made. Anecdotes run rife of ordinary Chinese investors selling their homes (as the housing market cools) or quitting their jobs to speculate in – or, as it's known colloquially in Mandarin, to "stir-fry" – stocks. Every significant sharemarket move is reported on the front pages of not just the financial dailies, but often on the more widely read city tabloids.

However, perhaps best encapsulating the sharemarket craze's mass appeal was a photo that went viral on Chinese social media this week of a street vendor selling bananas, engrossed on his laptop with share price graphs clearly visible on the screen. It evoked the famous anecdote of the "roaring twenties" just before the Great Depression hit, where famed US investor Joe Kennedy's shoeshine boy offered him a stock tip: "Buy Hindenburg." Instead, Kennedy sold all his holdings, thinking: "You know it's time to sell when shoeshine boys give you stock tips. This bull market is over." However, far from ringing alarm bells, even typically bearish China analysts consider it feasible that the sharemarket will continue its phenomenal run; for the simple reason that the Chinese government wants it to. "That this is the explicit government strategy is not in doubt," says Anne Stevenson-Yang of Beijing-based J Capital Research. "Each new week brings a new promotional policy, whether it is permitting the investment of pension funds in the equity markets . . . or just putting out positive news." Chinese authorities, from the securities regulator to central bank governor Zhou Xiaochuan, have publicly endorsed the flow of funds into equities.

China is trying to control credit expansion while protecting an economy that expanded 7.4 per cent last year, the slowest rate in a quarter of a decade. As one Bloomberg report succinctly put it, China Inc is turning to the sharemarket for a cure to its unprecedented debt hangover; essentially, appropriating public capital to push the economy forward amid a broader slowdown. Debt, fuelled by an overheated property sector, is a central concern for China's economic leaders. By stoking a bull market, Ms Stevenson-Yang says, monetary managers hope to transform a big chunk of the unpayable debt floating around into equity, thereby relieving companies of the burden of repayment and refinancing. And by creating a "wealth effect", investors who get richer also spend more, aiding the transition from an investment-led economy to one more driven by domestic consumption. However, there is no guarantee of success. While the vast majority of share trades and the registration of trading accounts now take place online, staff at the CITIC China Securities branch in central Beijing say they have seen at least a doubling in foot traffic from investors executing trades in person at the office's ageing automated terminals.

A study by China's Southwestern University of Finance and Economics found that two-thirds of new investors who created trading accounts last year did not complete high school; a reflection of the demographics of China's older mum and dad investors. However, it also a stark reminder of who is likely to get burnt most if the bubble bursts. "Overseas, you might have to look at the economy, but in China, if you trade shares you must listen to the government," retiree Sun Lianzeng, 63, says. "Share prices have been rising because the government is trying to expropriate money into the stock market. Everyone knows about it, and everyone is trying to make money from it." One investor at the China Securities office, dressed in pink, stands up suddenly, claps her hands together and beckons me over. "The foreign media, no, the whole world, should watch the Shanghai Stock Exchange, forget about Wall Street," she said, clearly enjoying a good day at the office.