"Whether it's this year or next year, the odds of another economic downturn are high — and growing," Warren says.Politicsread more
The agreement between the White House and congressional Democrats would raise the debt ceiling for two years and permanently end the sequester.Politicsread more
Equifax will give consumers a range of options for monitoring their credit or making claims of fraud or data misuse, part of a $425 million restitution fund.Technologyread more
Microsoft and OpenAI announced a new partnership to build artificial general intelligence to tackle more complex tasks than current AI.Technologyread more
A group of gold miners stocks "BAANG" are better plays than mega-cap FAANG names, according to John Roque, technical analyst at Wolfe Research.Marketsread more
The Iranian Intelligence Ministry held a briefing on Monday where they announced the alleged spies were Iranian citizens but trained by the CIA.World Newsread more
Two traders say Boeing's on the path to recovery.Trading Nationread more
Documents leaked to The Washington Post revealed that Huawei secretly worked with the North Korean government on its wireless network.Technologyread more
Equifax will pay at least $575 million, and potentially as much as $700 million, to settle allegations over its massive over 2017 data breach, U.S. regulators said in a...Technologyread more
CNBC's Mike Santoli breaks down the aggressive buying of "sure things" and shunning of cyclical and policy risk.Trading Nationread more
Facebook has seen an increase in the median number of comments, likes and ads clicked by users on the service from January to July, according to Audience Insights, a Facebook...Technologyread more
Whether China shares are in a bubble depends on which data bit catches the fancy, but the market has outstripped its fundamentals and is 23 percent overbought, Credit Suisse said.
"Margins, profitability and value creation continue declining as productivity growth lags real wage growth and product selling prices are eroded," Credit Suisse said in a note Friday.
"Moreover, equity market price momentum has decoupled away from earnings revisions which remain deeply embedded in negative territory."
Its models indicate the market is 23 percent overbought and has potential downside of 15 percent in U.S. dollar terms by year-end.
Read More China's see-saw ride? Don't sweat it
The mainland's shares have rallied sharply this year, despite a brief drop into correction territory last week. The is up around 50 percent year-to-date, even after last week's one-day 6.5 percent plunge. The Shenzhen Composite is up around 111 percent year-to-date.
Credit Suisse attributes the rally to factors including the People's Bank of China injecting liquidity through its easing measures, retail investors re-allocating assets to stocks and away from bank savings, wealth management products and property. Apart from some restrictions on margin trading, the securities regulator also appears to be letting the rally ride, the bank noted.
But is it a bubble?
"The evidence for is largely participation and technicals related," the bank said. "The evidence against is principally valuation related."
Supporting the bubble view, new share-trading account openings remain elevated and the markets' average daily trading value has surged to records, it noted. In addition, technical indicators such as deviations from the 200-day moving average and the relative strength index are now comparable to the 2007 A-share bubble, it said.
The Shanghai Composite hit its all-time high of 6124 in October of 2007, as the Global Financial Crisis was brewing.
However, while the current relative valuation of the mainland-listed A-shares and Hong Kong-listed H-shares is elevated, it remains far below peaks hit in 2008, Credit Suisse noted. Other metrics, such as earnings yield-to-bond-yield, price-to-earnings and price-to-book, are actually significantly more favorable than their 2007 levels, it noted.
Some are more certain about which indicator will call a bubble.
"Looking at the market cap to GDP (gross domestic product) ratio as a measure of risk in equity markets, it now seems to us that the recent sharp rise in the Chinese market is the first sign of a bubble without the support of fundamentals," Societe Generale said in a note Monday. The ratio grew by 124 percent over the past 12 months, similar to the climb in 2006-2007, it noted.
"The Chinese equity market should therefore be closely monitored this summer," it said.
To be sure, many remain positive on China shares.
Nomura, for one, has a three-year bullish view, although it is "tactically cautious" for the current quarter. It's looking at China's reform efforts, particularly toward opening its capital markets. It expects more long-term institutional funds will enter mainland markets over time. Index creators FTSE and MSCI are heading toward including mainland shares as well, it noted.
—By CNBC.Com's Leslie Shaffer; Follow her on Twitter