Stock Index Fund
U.S. stock index fund · tracks S&P 500 Index
As of its 2026 Q2 report, Stock Index Fund held 508 positions with $7.16B in net assets. Its ten largest holdings made up 39.0% of the fund. The VSTIX share class costs 0.23% a year. Over the 12 months to May 2026, VSTIX returned 29.5%, with dividends reinvested. In 2026 Q2 it added 11 new positions and exited 9.
The Fund seeks long-term capital growth through investment in common stocks that, as a group, are expected to provide investment results closely corresponding to the performance of the S&P 500 Index (the Index).
The fund is managed by a subadviser to track the S&P 500 Index by purchasing either all index stocks in their same proportions or a representative sample selected through optimization to match the index's industry weightings, market capitalizations, and fundamental characteristics. Because the fund may use sampling rather than holding all index constituents, its performance may diverge from the index. The subadviser may employ derivatives including futures and total return swaps to seek index tracking, and the fund may lend securities to generate additional income.
What you own
| Company | Weight | Value | Shares | Reported price |
|---|---|---|---|---|
NVDANVIDIA Corp | 7.85% | $562.05M | 2.7M | $211.14 |
AAPLApple Inc | 7.01% | $501.87M | 1.6M | $312.06 |
MSFTMicrosoft Corp | 5.11% | $366.25M | 813.5K | $450.24 |
AMZNAmazon.com Inc | 4.04% | $289.62M | 1.1M | $270.64 |
GOOGLAlphabet Inc | 3.39% | $242.57M | 637.8K | $380.34 |
AVGOBroadcom Inc | 3.24% | $232.05M | 519.4K | $446.77 |
GOOGAlphabet Inc | 2.69% | $192.85M | 512.3K | $376.43 |
2.12% | $151.55M | 239.6K | $632.51 | |
TSLATesla Inc | 1.88% | $134.26M | 308.1K | $435.79 |
1.67% | $119.72M | 123.3K | $971.00 |
Reported price is the fund's own reported value divided by its own reported shares at 2026-05-31 — not a live quote, and not what the fund paid.
The 200 largest of 508 holdings, with the share counts as filed, open with a free account.
What the fund is made of
Percentages are of fund net assets. Rounding, liabilities and short positions can make totals differ from 100%.
| Stocks | 99.86% |
| Cash & short-term | 0.05% |
| Derivatives | 0.01% |
Look-through blends 1 underlying fund; 0.511% of NAV was not looked through and stays direct-classified.
By sector
- Information Technology
- 37.8%
- Financials
- 11.0%
- Communication Services
- 10.3%
- Consumer Discretionary
- 9.6%
- 10 other sectors
- 31.3%
- Information Technology
- 37.8%
- Financials
- 11.0%
- Communication Services
- 10.3%
- Consumer Discretionary
- 9.6%
- Health Care
- 8.1%
- Industrials
- 7.7%
- Consumer Staples
- 4.5%
- Energy
- 3.1%
- Utilities
- 2.1%
- International
- 2.0%
- Real Estate
- 1.8%
- Materials
- 1.4%
- Other
- 0.5%
- Cash
- 0.1%
How it has done
VSTIX share class · total returns with dividends reinvested
Volatility over the last 12 months: 13.12%. Past returns are a record, not a forecast.
Fees & fund details
Stock Index Fund is a U.S. equity index fund that tracks the S&P 500 Index. 21% of VSTIX’s stock holdings are in companies whose revenue grew in the top quartile of U.S. companies over the last five fiscal years (covering 97% of the fund’s equity).
- Asset class
- Equity
- Region
- United States
- Management
- Index (passive)
- Fund type
- Open-end fund
- Expense ratio, by class
- 0.23%· VSTIX 0.23%
- Portfolio turnover
- 3.00% a year · as of 2025 Q3
Net is what a holder pays after the adviser's contractual waiver; gross is before it. A waiver can expire.
Turnover is how much of the portfolio was replaced in a year.
Classified from what the fund holds, not from its name · 2026 Q2. The summary is a paraphrase of the prospectus; the objective is verbatim.
What changed this quarter
Positions that entered or left the fund since its previous filing. Positions that were only resized are not listed.
11 new· the largest 8
9 exited· the largest 8
Understand how this fund fits with the rest.
Explore shared holdings, compare funds and follow their businesses with your connected AI:
- “Where do my funds overlap — VSTIX, QQQ and the fund in my 401(k)?”
- “How do this fund’s ten biggest holdings stack up against each other?”
- “For my target-date fund, what’s the real stock-and-bond mix once you look through it?”