The short version

Most TSP funds finished Friday, Jan. 2, higher. The S Fund led at +1.25%, the only individual fund above 1%. The I Fund was close behind at +0.97%. The F Fund slipped 0.10%, and the G Fund did what it does, edging up 0.02%.

One caution on the numbers. Every fund shows a year-to-date change of 0.0%, which can't be right for a first trading day with moves this size, so I'm leaving that column out. The index and ETF figures below are from the prior session's close, so they won't line up exactly with the TSP share prices.

How the TSP funds did

C Fund (S&P 500): $109.7449, +0.21%. That matches the S&P 500's +0.19% closely, which is what you'd expect from a fund that tracks it. Over five days it is still down 1.02%.

S Fund (Dow Jones U.S. Completion): $101.6677, +1.25%. This is the spike of the day. The fund holds mid-size and smaller companies, the part of the U.S. market outside the S&P 500, and those stocks can swing harder than large caps. The five-day figure is still -1.02%, so the jump only softened a rough week.

I Fund (MSCI ACWI ex-US ex-China): $56.0292, +0.97%. Just under the 1% line. Its five-day gain is 0.9%, so most of that gain arrived in this one session.

F Fund (Bloomberg U.S. Aggregate): $20.8602, -0.10%. Bond prices tend to ease when yields rise, and the 10-year Treasury yield ticked up, covered below.

G Fund (Treasury rate): $19.5922, +0.02%. It earns an interest rate and has no price swings, so it barely moves.

L Funds

The L Funds blend the five core funds, so their results follow how much stock each one holds. L Income, the most conservative, gained 0.18%. L 2030 rose 0.35%, L 2040 rose 0.44%, and L 2050 rose 0.50%. The longest-dated funds, L 2055 through L 2070, all gained about 0.61%, with L 2075 at 0.60%. More stock exposure meant a bigger gain on a day when stocks rose.

The five-day picture runs the other way. Every L Fund except Income is down between 0.18% and 0.35%, and L Income is off 0.03%. The same stock-heavy mix that helped Friday hurt over the week.

What moved IRA index funds and ETFs

Among the major indexes, the Dow Jones Industrial Average gained 0.66% to 48,382.39 and the S&P 500 rose 0.19% to 6,858.47. The Nasdaq Composite slipped 0.03% to 23,235.63. The data doesn't say why, but it shows large industrial names doing better than the tech-heavy Nasdaq.

The Vanguard Total Stock Market ETF (VTI) rose 0.31% to $336.31. Broad U.S. funds like this one sit between the S&P 500 and the small-cap-heavy S Fund, and VTI's result falls between them.

The Vanguard Total International Stock ETF (VXUS) rose 1.46% to $76.54, the biggest mover on the list. It is broader than the TSP's I Fund because it includes China, so the two won't match, though both had a strong day.

The Vanguard Total Bond Market ETF (BND) fell 0.04% to $74.04. The 10-year Treasury yield rose 0.58% to 4.187%, roughly 2 basis points higher. Rising yields and slightly lower bond prices usually go together, and that is what the F Fund and BND both showed.

What it means for your plan

One session is a small piece of a long timeline. A 1.25% day in the S Fund is worth noticing, but with the C and S Funds both still down about 1% on the week, it hasn't changed much.

If you hold a mix of funds or a target-date fund, you saw this spread across your holdings automatically. That is the purpose of diversification. This recap is general information, not advice for your situation. Your contribution rate, time horizon, and goals matter far more than any single day's numbers.