Overstock.com ( OSTK) announced a 52% reduction in its auction listing fees Wednesday, roughly matching the magnitude of a recent fee hike at rival eBay ( EBAY). The company also said the number of listings on its Overstock.com Auctions has risen 50% in the five days since eBay's announcement. "That's a significant jump," the company opined. "Clearly there's growing rancor among eBay's community of sellers." Overstock's volatile stock added $2.09, or 3.4%, to $64.10 on the news, though it remains down about 7.6% this year. eBay announced last week that starting Feb. 18, the monthly fee for merchants running a store on its Web site will rise 60% to $15.95 from $9.95. A fee for 10-day listings will double to 40 cents.