Qihoo (QIHU +0.8%) has spiked lower after Muddy Waters joins fellow Chinese short-seller Citron...

Qihoo (QIHU +0.8%) has spiked lower after Muddy Waters joins fellow Chinese short-seller Citron Research in attacking Qihoo's business practices. MW notes merchants using Alibaba's popular Taobao platform accuse Qihoo of diverting commissions to other accounts by means of code within its 360 browser, and that some have begun a Boycott 360 campaign. Shares were previously up strongly thanks to a bullish note from Macquarie: the firm says checks indicate healthy business trends for Q4 and Q1.