Sept 28 (Reuters) - Shares of Amplitude Inc opened nearly 43% above their reference price in Nasdaq debut on Tuesday, notching up a valuation of about $5 billion for the Benchmark Capital-backed analytics company. San Francisco-based Amplitude, which confidentially filed for a direct listing in July, was valued at $4 billion after a funding round in June. Stock of the company, which is also backed by Tencent Holdings Ltd, Sequoia Capital and Singapore’s sovereign wealth fund GIC, opened at $50 per share, up from the reference price of $35 per share. Amplitude is a mobile analytics company that enables customers to optimize their products. Its customers include Comcast-owned media company NBCUniversal, payments processor PayPal Holdings Ltd, fitness products maker Peloton Interactive Inc and grocery delivery firm Instacart. In a direct listing, companies are allowed to list on the stock market without selling shares. Amplitude’s co-founder and Chief Executive Officer Spenser Skates has long been a proponent of this alternative route to public markets. (Reporting by Niket Nishant in Bengaluru; Editing by Shinjini Ganguli) Our Standards: The Thomson Reuters Trust Principles.