Sept 29 (Reuters) - Shares of Warby Parker Inc jumped 35% in their U.S. market debut on Wednesday, notching up a valuation of over $6 billion for the eyewear company. The company"s stock, which went public through a direct listing, opened at $54.05 per share compared with the reference price of $40 per share. A direct listing lets companies list their stock on exchanges without selling shares, thereby sidestepping a costly and time-consuming initial public offering. Tiger Global Management, General Catalyst, Baillie Gifford and D1 Capital Partners are investors in Warby. It had confidentially filed for a listing in June. read more