I think looking at 13Fs is helpful but there are some caveats to the approach. First, if a fund is known to trade pretty frequently/have tons of turnover, the

I think looking at 13Fs is helpful but there are some caveats to the approach. First, if a fund is known to trade pretty frequently/have tons of turnover, the 13F might be bad to look at. In addition, many funds are not simply long-only vehicles. A lot of them will be doing some shorting, stuff outside of the US, or macro fixed income commodity currency strategies that wont be reflected in the 13F positions. Still, 13Fs are useful, especially from an idea-generation perspective. Definitely a cool tool, I use something similar.