SHANGHAI, June 5 (Reuters) - China stocks had another bumpy ride on Friday as both main indexes erased losses in the afternoon and ended the day at fresh seven-year closing highs.
But Shenzhen's ChiNext index, bellwether of the recent bull run, lost ground, with investors becoming increasingly cautious about a growth market that U.S. bond king Bill Gross called the "short of a lifetime".
The CSI300 index of the largest listed companies in Shanghai and Shenzhen rose 1.0 percent, to 5,230.55.
The Shanghai Composite Index gained 1.5 percent, to 5,023.10 points, its first closing above 5,000 in seven years. ChiNext lost 0.9 percent.
For the week, SSEC gained 8.9 percent and CSI300 produced 8.1 percent, their biggest weekly rises since early December.
The Shenzhen market has caught the attention of Gross, erstwhile Pacific Investment Management Co bond king and now portfolio manager of the Janus Global Unconstrained Bond Fund.
He said in his twitter account on Wednesday that China's Shenzhen market would be the next "short of a lifetime", but "not just yet."
Premier Li Keqiang said the government would promote domestic listings of start-up firms, while a growing number of Chinese tech companies firms have fallen out of love with America, as they look to drop their listings in New York and head back home.
And on Friday, major Chinese brokerage CITIC Securities Co Ltd moved to tighten margin trading rules for the second time in less than a month, offering fresh signs that a government-directed campaign to reduce leverage in China's red-hot stock market is accelerating.
The banking index lost 1 percent as investors took profit, while real estate stocks were firmer, up 3.3 percent. (Reporting by Samuel Shen and Pete Sweeney; Editing by Richard Borsuk)