Chinese ADRs rallied in Monday trading. TAL Education rose 20%; iQiyi rallied 17%; NIO surged 13.6%; KE Holdings soared 13%; Bilibili rose 9%; Li Auto rose 8%; XPeng rose 5%; JD.com rose 4.7%; PDD rose 4.3%; Alibaba rose 3.3%.

China benchmark index posted the biggest gain since 2008 on Monday, entering a bull market. The rush into the market before a weeklong holiday has also sent trading turnover to a record high. The interest was so intense that broker applications collapsed and requests for opening trading accounts surged, according to local media.

The latest leap came after three of China’s largest cities relaxed rules for homebuyers, while the central bank also moved to lower mortgage rates. The measures were among the key elements of a sweeping stimulus package released last Tuesday that also included interest rate cuts, freeing-up of cash for banks, as well as liquidity support for stocks.

For Winnie Wu, chief China equity strategist at BofA Securities, caution still lingers with many of her clients asking whether it’s time to take profit after a few days of strong gains.

“It’s really hard to either chase the rally or adjust positions. It’s a very exciting time, but it is also a very difficult, challenging, painful time for many investors,” she said.

So far, the fear of missing out is palpable. Brokerages, typically seen as a barometer for market sentiment, led gains Monday with many posting double-digit jump. A Bloomberg Intelligence gauge of Chinese property developers rose as much as 15.7%. Hedge funds are selling US technology stocks and piling into mining and materials firms. Meanwhile, iron ore spiked about 11% as investors bet that China’s efforts to ease property woes will improve demand from the world’s top consumer of the steel-making ingredient.

The Fear and Greed Indicator of the Shanghai Composite Index, which measures the buying and selling momentum for the stock benchmark popular among China’s retail investors, rose to the highest since 2015 on Monday.

“This is an epic day in the Chinese market history,” said Hao Hong, chief economist at Grow Investment Group. “This is one of the happiest days” of his 30 years covering the Chinese market, he added.

Some are urging cooler heads, after being burned chasing past rallies in Chinese stocks.

“I must confess, after busily gobbling on this week-long policy banquet, my concern about a potential replay of the previous disappointing cycle lingers,” said Hebe Chen, an analyst at IG Markets Ltd. “It’s still too early to tell if this ‘Golden-Week rush’ will blossom into a true gold rush or fizzle out into another mirage.”