The short version

Stocks had a soft Wednesday, and small and mid-size companies took the worst of it. The S Fund dropped 1.55%, the only TSP move over 1%. The C Fund slipped 0.53%. The bond and international funds barely moved.

Individual funds

S Fund (-1.55%, $99.9358). This is the standout. The S Fund tracks the Dow Jones U.S. Completion index, which is the U.S. market minus the S&P 500, so it leans on mid-size and smaller companies. It fell almost three times as much as the C Fund. Its 5-day return is now -1.77%, the only negative five-day number on the board. Even so, it is up 10.55% for the year.

C Fund (-0.53%, $106.9167). It follows the S&P 500, which fell 0.53% to 6699.4. The match is exact, as it should be. The C Fund is still up 15.31% year to date and 0.43% over five days.

I Fund (+0.01%, $53.3218). It tracks MSCI ACWI ex-US ex-China, and it finished essentially flat. It leads the lineup for the year at 27.17% and has gained 0.61% over five days.

F Fund (+0.01%, $20.9495) follows the Bloomberg U.S. Aggregate bond index. It was flat on the day, up 0.53% over five days and 7.54% this year.

G Fund (+0.01%, $19.4314) earns a Treasury-based rate, so it just ticks up. It has gained 0.08% over five days and 3.59% this year.

L Funds

The lifecycle funds blend the five core funds, so their day depended on how much stock each one holds. The 2030 fund lost 0.27% and the 2035 fund lost 0.31%. The 2040 fund fell 0.34%, the 2045 fund 0.36%, and the 2050 fund 0.39%. Every fund from 2055 through 2075 fell 0.47%. L Income, the most conservative blend, lost just 0.12%.

The pattern is simple. More stock means a bigger dip on a down day, and more bonds and G Fund means a smaller one. Five-day gains for the dated funds sit in a narrow 0.18% to 0.22% band.

What moved IRA index funds and ETFs

The index figures below are tagged as the prior session close, though the S&P's 0.53% drop matches the C Fund's move exactly.

The Nasdaq Composite fell 0.93% to 22740.4, the largest loss among the major indexes. The Dow dropped 0.71% to 46590.41. The Vanguard Total Stock Market ETF (VTI) lost 0.61% to $328.90, which fits, since it holds the whole U.S. market and sits close to the S&P's decline.

Outside U.S. stocks, things were quiet. The Vanguard Total International Stock ETF (VXUS) rose 0.08% to $74.28. The gap between that and the I Fund's 0.01% is small. The two follow slightly different indexes, and VXUS includes China while the I Fund does not.

The Vanguard Total Bond Market ETF (BND) finished flat at $75.07. The 10-year Treasury yield eased 0.25% to 3.953, which gave bonds a stable backdrop.

What it means for your plan

A 1.55% drop in one fund on one Wednesday is a small event in a plan built over decades. The S Fund's slide shows why many people hold a mix. The C and I funds, the bond funds, and the L Funds all landed much closer to flat than the S Fund did.

If you hold a lifecycle fund or a diversified IRA mix, today's numbers are mostly a reminder of how the pieces behave. One day rarely matters for a long-term plan, and the year-to-date figures still look solid across the board.