While it’s easy to read too much into 13Fs, the time delay and the single snapshot after a quarter of activity make them hard to interpret, they’re still one of the few tools we have to gauge the changing interest that investment funds have in the markets, and looking for big shifts can point to attractive investments (aggregate data via Bloomberg, Edgar, Dataroma). Also see 13F Filings For Q2: Buffett, Loeb, Einhorn, Druckenmiller, Griffin, Berkowitz, Tepper, Mandel 13F – Top new/increased positions for 2Q14 National-Oilwell Varco, Inc. (NYSE:NOV) had the most interest from institutional investors last quarter including a 43% bump…