|        By William L.        Watts, MarketWatch         | Bitcoin            turmoil puts big money, reputations on line |  
 So far, there's little sign big investors in        bitcoin and bitcoin-related ventures are ready to abandon ship after the        collapse of bitcoin exchange Mt. Gox, even as the fiasco triggers        recriminations and new calls for regulation.
 
 Suffice to say, the        situation isn't welcome news for advocates of the virtual currency who        have touted it as a long-term alternative to government-issued currency.        One of their main arguments, after all, is that it is safer and sounder        than currencies like the dollar and yen. Venture capital firms poured        around $74 million into bitcoin-related ventures in 2013, according to        CB Insights. Here's a guide to some of the biggest players.
 
 Read        about the Mt. Gox's CEO statement and how bitcoin prices are rebounding        Wednesday.
 
 Listen to Chuck Jaffe: What happens now if you hold        bitcoin
 
 -- William L. Watts @wlwatts
 
 -William L. Watts;        415-439-6400; AskNewswires@dowjones.com
 
 Marc Andreessen
 
 Among        the most high-profile bitcoin backers is Marc Andreessen, the co-founder        of Netscape and general partner of venture-capital firm Andreessen        Horowitz. That firm has made around $50 million in investments in        bitcoin-related ventures, according to the New York Times. Andreesen        personally holds only what paper described in January as a "de minimis"        amount of the virtual currency.
 
 Earlier this year, he penned a        column for the Times's Dealbook site praising bitcoin as a piece of        transformational technology with a bright future ahead, putting it on        par with personal computers circa 1975 or the Internet in 1993.
 
 Andreessen        Horowitz led the largest bitcoin investment to date, a $25 million        funding round for bitcoin wallet Coinbase, according to CB Insights.        Andreesen Horowitz didn't respond to an email seeking comment on the        latest bitcoin turmoil on Tuesday.
 
 Andreessen, on Twitter, said        Tuesday it was important to remember that every new technology,        including the personal computer and Internet, also had birthing pains.        "Our enthusiasm and commitment unchanged," he tweeted.
 
 -William        L. Watts; 415-439-6400; AskNewswires@dowjones.com
 
 Winklevoss Twins
 
 Tyler        and Cameron Winklevoss last week launched the Winkdex, an instrument        designed to establish the underlying value of a bitcoin, a calculation        that was complicated before the latest Mt. Gox trouble by different        values across various exchanges.
 
 The twins, whose lawsuit against        Mark Zuckerberg over the origins of Facebook was dramatized in the 2010        hit movie "The Social Network," popped back up on the radar screen when        they announced last April that they had bought $11 million worth of        bitcoin and then last summer filed papers with the Securities and        Exchange Commission to establish the first bitcoin exchange-traded fund.        Winklevoss Capital didn't respond to a request for comment on Tuesday.
 
 -William        L. Watts; 415-439-6400; AskNewswires@dowjones.com
 
 Fred Wilson
 
 The        managing partner of Union Square Ventures, which counts Coinbase as a        portfolio company, wasn't running scared on Tuesday. Writing on his        blog, Wilson said the Mt. Gox woes were potentially a "sad day" for the        bitcoin sector, but emphasized that the "wonderful thing about a        globally distributed financial network is that if one of the nodes go        down, it doesn't take the system down." He likened bitcoin's        architecture to that of the Internet, with no "centralized control        point" or "single point of failure."
 
 Moreover, he        noted that much of the venture capital pouring into the sector is going        to infrastructure, which will help reinforce the ability of institutions        to live up to their custodial roles. And he added that he "bought a        little bitcoin" on Tuesday.
 
 "Not much. But I always feel        good buying when there is blood in the streets in any market. It is my        favorite time to buy," Wilson wrote.
 
 -William L. Watts;        415-439-6400; AskNewswires@dowjones.com
 
 Michael Novogratz
 
 The        principal of hedge-fund firm Fortress Investment Group made headlines        last fall when he said bitcoin was just starting to heat up. At a        conference in October, he said he'd bought bitcoins a few months        earlier. As bitcoin rallied in November, he told MarketWatch that prices        would go higher and that it was just the third inning of a nine-inning        game.
 
 Fortune in December reported that Fortress was preparing        its own bitcoin hedge fund. Novogratz didn't immediately respond to an        email requesting comment.
 
 -William L. Watts; 415-439-6400;        AskNewswires@dowjones.com
 
 Jim Breyer
 
 Breyer, an early        investor in Facebook Inc. (FB)        and managing partner at venture capital firm Accel Partners, contributed        to a $9 million funding round last October for digital currency company        Circle Internet Financial.
 
 At the time, Brewer said he was        confident that "you will see major worldwide retailers adopting systems        built on bitcoin." An Accel spokeswoman didn't immediately respond to        requests for comment. Circle joined Coinbase and four other firms in        issuing a joint statement pledging to safeguard customer security in the        wake of the Mt. Gox situation.
 
 -William L. Watts; 415-439-6400;        AskNewswires@dowjones.com
 
 Barry Silbert
 
 Silbert, the        founder of SecondMarket and the Bitcoin Investment Trust, a private        trust for wealthy investors, sees a vacuum in the wake of the Mt. Gox        fiasco. Silbert, who has invested in several bitcoin-related startups,        told MarketWatch that he is in the process of creating a bitcoin        exchange in close collaboration with regulators.
 
 "[We're] doing        this in a way where regulators are involved really from Day One," he        said. The exchange won't be a SecondMarket venue, he said. Instead,        Silbert plans to spin off SecondMarket's bitcoin business into a        separate company and assume the title of CEO of both companies. There        will be two business lines: The Bitcoin Investment Trust, and the        bitcoin trading team, he said in an interview Tuesday.
 
 "We're        going to be contributing at least $20 million in cash," he said. If the        rumors are true, the sooner that Mt. Gox goes away, the better for        bitcoin, he said. -- Saumya Vaishampayan
 
 More on bitcoin:
 
 Mt.        Gox collapse riles bitcoin users, spurs regulatory calls
 
 David        Weidner: How bitcoin could turn it around
 
 Bitcoin exchanges try        to soothe customers
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