CHINA'S stockmarket has often been called a casino, with share prices bearing little connection to underlying economic conditions. But while the market has strayed from growth trends in the past, its divergence over the past few months has reached new extremes. Economic growth in the first quarter fell to 7%, the slowest annual figure in six years, but stocks have more than doubled in value since the middle of 2014. A shift to monetary easing and fiscal stimulus—and expectations of more of both—help explain why the rally began. But the longer it has continued, the more it has looked like a classic case of irrational exuberance. Here, we offer a look at the mania in charts.

Is the Chinese stockmarket in bubble territory? That depends on what part of it one focuses on. Large-cap stocks, long depressed, are arguably more fairly priced after the rally of the past year. Many banks are still trading at valuations lower than international peers. The same cannot be said for ChiNext, a board for start-ups, especially tech firms. Its price-to-earnings ratio has reached 130, more than twice a more reasonable level for companies with strong growth stories. ChiNext is supposed to be China’s answer to Nasdaq. At the moment it looks like precisely that in 1999, just before the dotcom bubble spectacularly burst.

Another measure of the stock mania in China is the gap that has opened between share prices in the mainland and Hong Kong. The same companies with shares listed in both markets now trade at a 30% premium in the mainland, not far from a five-year high. A new programme to link the markets was supposed to prevent such gaps, allowing investors to arbitrage the price differences. But "southbound" flows to Hong Kong have failed to take advantage of the lower prices there. Instead, investors believe that there is still more money to be made riding the mainland rally.

China had a stock bubble a short while ago, in 2006, followed by a crash in 2007. The shape of the bull run now looks similar, but there is one big difference. Last time, investors were not able to buy shares on credit. This time, the rules have been changed to allow margin financing, and investors have taken advantage of it. The outstanding volume for share financing has more than doubled over the past year to more than 2 trillion yuan, or about 3% of GDP. The fact that so much debt is underpinning the stock rally could make for a sharper, nastier correction when it ends.

The best indicator of just how much money has entered the stockmarket is the surge in openings of new trading accounts over the past year. Almost 8m accounts were opened in the first quarter of 2015. In April regulators allowed individuals to open up as many as 20 accounts (previously, they were restricted to one), a rule change that makes it easier for day traders. Since then, investors have opened about 4m accounts per week.

Who exactly are these investors? Conventional wisdom is that China’s market is full of small-time punters. That is true, up to a point: retail investors account for as much as 90% of daily turnover, whereas institutions dominate more developed markets. But many of the new investors in the Chinese market over the past year appear to be quite wealthy. Less than 20% of accounts in the past held more than 100,000 yuan ($16,000). Now, nearly 40% do. Partly, that is because the rally has inflated account values, but they have also swelled as a result of new cash inflows. China’s small investors now have bigger stakes in what is becoming a more dangerous game.