Mizuho analyst Difei Yang double downgraded Viveve Medical to Underperform from Buy and cut her price target for the shares to 20c from $4.00. The stock in premarket trading is down 24c, or 59%, to 17c. The company is facing a "cash crunch" after the Liberate clinical trial in stress urinary incontinence failed to meet its primary endpoint, Yang tells investors in a research note. The analyst sees two likely scenarios for Viveve: a potential sale of the company, or elevated risk of running out of cash. She sees elevated liquidity risk if Viveve is unable to attract investors.