SHANGHAI China resumed initial public offerings in January after a 14-month suspension, with 45 firms floating shares and raising a combined 32.1 billion yuan ($5.3 billion) in the month.
To support the resumption, the China Securities Regulatory Commission (CSRC) launched a slew of reforms in November but has been forced to pull back some and add new restrictions so as to curb irregularities, leading to dozens of firms postponing IPOs, although some have later re-launched IPOs after adjustments.
Here are the major events and setbacks for IPO reforms.
Nov 30 - The CSRC announces a slew of IPO reforms to boost the market to pave the way for IPO resumption in January, saying about 50 firms to be listed in the month.
Dec 14 - The CSRC issues fresh details on the reforms, eliminating pricing and turnover curbs for IPOs.
Dec 31 - Five companies publish share issue prospectuses to launch IPOs in January.
Jan 8 - Zhejiang Wolwo Bio-Pharmaceutical Co (300357.SZ) and Guangdong Xinbao Electrical Appliances (002705.SZ) become the first two IPO candidates to float shares, attracting heavy subscriptions.
Jan 10 - Drugmaker Jiangsu Aosaikang Pharmaceutical Co (300361.SZ) announces it will postpone its IPO due to problems including setting the issue price too high and trying to sell too many existing shares in the IPO.
Jan 12 - The CSRC says that any company that prices its IPO at a premium to its industrial peers in the secondary market, measured by the respective price-to-earnings (PE) ratios, must delay opening subscriptions to retail investors by three weeks.
Jan 13 - Five firms say they have postponed IPOs in response to the latest CSRC rules.
Jan 14 - Three companies decide to sell shares at valuations much lower than those of peers.
Jan 15 - The CSRC says it has begun inspections of IPO pricing behavior, targeting 13 underwriters and 44 institutional investors.
Jan 17 - Prices of Neway Valve shares (603699.SS) rise 43.5 percent on the first day of trading on the main Shanghai Stock Exchange in the mainland's first listing since the IPO resumption.
Jan 18 - In a rare case, Gansu Hongliang Leather Co (002720.SZ) announces it has put off its issue because of questions from the media about its financial data, including its profits.
Jan 20 - Shaanxi Coal Industry Co (601225.SS) raises 4 billion yuan ($661 million) in China's largest IPO since 2012, but cuts its fund-raising target by more than half partly because of the new regulations on pricing.
Jan 21 - Eight companies list on China's smaller Shenzhen Stock Exchange, the first listings on the bourse since IPOs resumed. All hit their daily limit-up levels and many continued jumping to limit-up in the following few days, reflecting huge speculative interest among Chinese retail investors in small caps.
Jan 26 - Zhejiang Wolwo and Chengdu Tianbao Heavy Industry Co (300362.SZ) announce trading in their shares to be suspended indefinitely after media reports alleged irregularities in their IPO.
Jan 27 - CSRC Chairman Xiao Gang admits that problems have appeared in the new IPO reforms, but reaffirms that the government will maintain market-oriented directions for reforms of the stock market.
Jan 27-29 - At the peak of new listings since the IPO resumption, 24 firms list in the Shanghai and Shenzhen bourses over three days. Shaanxi Coal jumps in its Shanghai debut on January 28, but plunges from the second day to near its IPO price, reflecting an investment culture shunning large-capitalization blue chips.
Feb 25 - The Shanghai stock exchange says it will investigate investment funds that purchased excessive amounts of shares during the IPO of Foshan Haitian Flavouring and Food Co.
March 27 - The CSRC makes a statement on its official microblog advising companies to choose the appropriate time to IPO, and encouraging them to list abroad or on OTC platforms. The statement is seen by many as an indication listings may be about to freeze again.
April 11 - The CSRC denies the IPO process has been once again frozen at a regular news conference.
April 16 - Sources confirm to Reuters that the CSRC has ordered underwriters to update application materials for firms waiting to list, raising hopes that IPOs may resume soon.
(Reporting By Lu Jianxin and Natalie Thomas; Editing by Kenneth Maxwell)