Nasdaq and Goldman Sachs set a reference price of $250 per share for Coinbase's (COIN) direct listing, CoinDesk reports.That puts the valuation of Coinbase at $66.5B, assuming an estimated 266.2M shares outstanding. It's the first major cryptocurrency business to go public in the U.S. and its value has surged along with the price of bitcoin and ethereum, the two main cryptos traded on its site.The reference price is calculated using public financial information and considers market sentiment as well.The per-share amount is 27% lower than Coinbase's last trade at the private secondary market at $343.58, according to Coindesk.MoffetNathanson set a $600 one-year price target for the stock, which it rates a Buy.Previously (April 13): Coinbase IPO buzz sends other cryptocurrencies higher