I'm confused as to what the actual rate of return was for the I Fund in 2025.
The TSP.gov website (A) says the overall return was 32.45%. However, if I add up all the monthly returns that that same website shows, I get 28.65%. The expense is only .042%, so that can't be what the difference is.
Does anyone know what the real rate of return was, and why the stated annual total doesn't equal the sum of all the monthly totals in that year?
Many thanks for any help offered!
(A) https://www.tsp.gov/fund-performance/
I Fund Performance Calculations for 2025
Moderator: Aitrus
Re: I Fund Performance Calculations for 2025
You do not sum the rates of return you multiply them in a compounding way. That’s because one months return applies to all the gains (or losses) of the prior months.
I.e.
(1.0368)(1.0091)(1.0002)(1.0416)(1.0497)(1.0373)(0.9848)(1.0395)(1.0316)(1.0213)(1.0042)(1.0304) - 1
= .3245 (approximately)
I.e.
(1.0368)(1.0091)(1.0002)(1.0416)(1.0497)(1.0373)(0.9848)(1.0395)(1.0316)(1.0213)(1.0042)(1.0304) - 1
= .3245 (approximately)
Re: I Fund Performance Calculations for 2025
Oh thank you, Newbits!
Fund Prices2026-05-15
| Fund | Price | Day | YTD |
| G | $19.90 | 0.01% | 1.60% |
| F | $20.76 | -0.62% | -0.60% |
| C | $119.03 | -1.22% | 8.69% |
| S | $108.28 | -1.95% | 7.84% |
| I | $61.97 | -2.08% | 11.68% |
| L2075 | $12.16 | -1.60% | 9.60% |
| L2070 | $13.92 | -1.60% | 9.60% |
| L2065 | $23.48 | -1.60% | 9.60% |
| L2060 | $23.48 | -1.60% | 9.60% |
| L2055 | $23.49 | -1.60% | 9.60% |
| L2050 | $44.90 | -1.36% | 8.07% |
| L2045 | $20.19 | -1.28% | 7.66% |
| L2040 | $72.71 | -1.20% | 7.27% |
| L2035 | $18.88 | -1.10% | 6.81% |
| L2030 | $61.55 | -0.93% | 5.94% |
| Linc | $30.34 | -0.48% | 3.75% |