Shares of government and retail surplus seller Liquidity Services (LQDT) dived Wednesday, as the company's stock has been on the down-slide for the past week over concerns about new competition from eBay (EBAY) and CEO Bill Angrick's stock sales. Liquidity shares were down nearly 7%, near 53.40, in midday trading Wednesday, after earlier tumbling as much as 13%. Shares are down 19% since hitting a June high of 65.86 on June 7. That was just off