Alibaba stock tumbled 11% Thursday after the company announced its quarterly results and cut its sales outlook for the full year. The Chinese e-commerce giant reported a 29% year on year revenue growth to $31.1 billion for the quarter ended September. Earnings per share fell 38% year on year to $1.74 apiece, below expectations. The company also slashed its revenue guidance for its current fiscal year to between 20% and 23% year-on-year growth, compared with what would have been 29.5% growth for the period. [Alibaba press release]