Juby Babu / Reuters:eBay reports Q4 revenue up 1% YoY to $2.6B, GMV up 4% YoY to $19.3B, and forecasts Q1 revenue below expectations; EBAY drops 7%+ after hours — E-commerce firm eBay (EBAY.O) forecast first-quarter revenue below Wall Street estimates on Wednesday, signaling weak demand for products such as collector's items and refurbished goods.