VGTSX vs. I Fund?

[uknowwho]

Why is there such a disparity in the rate of return between Vanguard's Total International Stock index fund and the TSP I Fund? YTD returns are as Follows:

VGTSX: 14.09%
I Fund: 10.76%

Thats a 3.33% advantage to Vanguard.

I also notice that on certain days when VGTSX has a gain the I Fund has a loss and vice versa, why is that?

 

[tsptalk]

You want to look at an EAFE index fund for a better comparison.

 

[James48843]

I find does not track Vanguard.

Very different allocations.

 

[uknowwho]

You want to look at an EAFE index fund for a better comparison.

How much difference is there between the two funds holding? I checked the holdings and they appear very similar.