Image source: Renren.   

It was a rough week for investors in some of China's lesser known dot-coms that trade on stateside exchanges. Shares of Renren (NYSE:RENN), Bitauto (NYSE:BITA), and Vipshop (NYSE:VIPS) all posted double-digit percentage declines. 

The market has been generally skittish about China's second-tier growth stocks. Let's take a look at why these three names came undone over the past week.

Renren: down 18%

Things continue to get worse for the company behind a fading social-networking platform. Renren posted disappointing quarterly results on Monday. Revenue from advertising and Internet value-added services plunged 25% since the prior year's quarter, as monthly unique logins fell from 46 million to 41 million over the past year. 

Overall revenue moved higher at Renren, but that's the result of its recent push into consumer financing. There's money to be made in providing consumer and auto-loan financing, but it's a model that comes with its fair share of risks.

Renren hasn't been profitable in a long time. It has now rattled off five years of operating losses. The saving grace is its healthy balance sheet, brimming with nearly $1 billion in cash and long-term investments. Unfortunately its guidance calls for continuing weakness.

Vipshop: down 13%

Chinese shopping site Vipshop also took a hit after posting unsettling financials. The provider of flash sales -- offering deep discounts on brand-name apparel -- is still growing at a heady clip. Revenue soared 41% to $1.89 billion since the prior year's first quarter. Earnings and adjusted earnings grew at a slower rate, but still managed to beat expectations with double-digit percentage growth. That wasn't the case at the top line where analysts were holding out for more, even though it was well within its forecast back in February for growth between 37% and 43%.

Its guidance also didn't satisfy sales growth concerns. Vipshop sees year-over-year growth of 37% to 42% for the current quarter. That may be in line with its most recent quarter, but Wall Street pros were holding out for slightly more if we go with the midpoint of Vipshop's range.

The average order size is shrinking at Vipshop, as the number of active customers and orders placed clocked in with growth north of 50%. JPMorgan downgraded the stock on Tuesday, and by Friday it was hitting fresh 52-week lows. 

Bitauto: down 13%

Unlike Renren and Vipshop, Bitauto didn't deliver rough quarterly financials last week. It did that a week earlier. China's leading provider of online content and marketing services for the auto industry posted healthy growth and earnings, but at least one major analyst wasn't impressed. 

Morgan Stanley waited until Monday of last week to downgrade Bitauto. Analyst Amanda Chen singles out a slowdown in ad subscriptions and concerns about the sustainability of its aggressive transaction monetization. She is slashing the price target from $28 to $20, and that was bad news for the stock since it began the week just above the $20 mark. It didn't finish off the week there, making Bitauto the third former Chinese dot-com darling Mr. Market marked down. 

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