"I'm very bullish on the future of twitter, for example. I think they really have a shot to become the first continuously up dated global brain," he says. In terms of your investment style, i know you're a generalist, but take me through how you decide to buy or sell a security, and then i may t ask you about alternate investments as well. "That's something i've tried to think about for a long time. Because here, again, it's very easy to copy someone else's style." 'It takes years to get to that kind of level of knowledge about a company'