Coinbase promised investors a modicum of security in the nascent bitcoin market this week when the San Francisco startup opened what it calls the first regulated U.S. trading post for the digital currency. Coinbase Exchange, which allows users to trade bitcoins, says it’s insured against accidental loss, hacking and internal theft. [...] the California Department of Business Oversight says it has not issued any licenses for digital currency exchanges, meaning the state has not investigated the company to determine whether it is safe for consumers. Like Western Union and PayPal, Coinbase’s exchange would probably be regulated as a money transmitter in California, Dresslar said, adding, “We have not made a decision about whether to regulate virtual currency under our money transmitter statute.” Venture capitalists see bitcoin as the future for money transfers: Since there’s no middleman, they say some transactions, like micro-payments and cross-border transactions, are less expensive with virtual currency. The FBI has shuttered online marketplaces where the digital currency was used to buy and sell illicit drugs. Last week, Coinbase announced a $75 million round of funding that included institutional investors like the New York Stock Exchange in addition to venture capitalists. Last week, Internet entrepreneurs Cameron and Tyler Winklevoss announced plans for Gemini, which they called “a fully regulated, fully compliant ...