TWCUX — Ultra Fund, Investor Class
Data updated: 2026-09-29
TWCUX — Ultra Fund, Investor Class. 0.87% expense ratio · no sales load · since 1981 · Trading - Leveraged. Holdings, fees, performance and SEC filings.
TWCUX Fund Overview
TWCUX — Ultra Fund, Investor Class is a US mutual fund managed by American Century Investment Management, Inc., categorised as Trading - Leveraged. ABC INVEST provides holdings, performance, costs, cashflows, risk data, prospectus documents and SEC filings, sourced from SEC filings.
- Type: US mutual fund
- Adviser: American Century Investment Management, Inc.
- Trust: American Century Mutual Funds, Inc.
- Category: Trading - Leveraged
- Minimum investment: $2,500
- Additional investment: $50
- Inception date: November 2, 1981
- Assets under management: $25.79B
- 1-year return: 9.3%
- Ticker: TWCUX
- SEC CIK: 0000100334
- SEC series ID: S000006195
- Share class ID: C000017060
- FIGI: BBG000BBR9L0
- LEI: F6OVJ18MFLNHYYI4ZV69
About TWCUX
Ultra Fund (TWCUX) seeks long-term capital growth by investing in stocks of larger-sized companies that managers believe will increase in value over time. Selection focuses on individual companies whose earnings or revenues are growing or accelerating, along with signs of business improvement and price strength relative to peers. The fund primarily invests in U.S. securities, may hold foreign companies, and may write covered calls on a portion of its common stock holdings. Its Investor Class shares, launched November 2, 1981, cost 0.87% a year and returned 9.3% in the 12 months to July 31, 2026, based on monthly returns reported to the SEC on Form N-PORT, with 18.2% volatility.
TWCUX Holdings
Top 10 holdings of Ultra Fund by percentage of net assets, from the fund's latest SEC N-PORT filing.
| Holding | % of net assets |
|---|---|
| NVIDIA Corp | 16.05% |
| Alphabet Inc | 6.37% |
| Microsoft Corp | 6.26% |
| Amazon.com Inc | 5.93% |
| Apple Inc | 5.91% |
| Alphabet Inc | 5.54% |
| Eli Lilly & Co | 3.46% |
| Tesla Inc | 3.37% |
| Mastercard Inc | 3.32% |
| Meta Platforms Inc | 2.82% |
TWCUX Portfolio Allocation
Asset-class allocation of Ultra Fund by percentage of net assets, from the latest SEC N-PORT filing.
| Asset class | Allocation |
|---|---|
| Equity | 99.9% |
| Cash & Equivalents | 0.4% |
TWCUX Performance
Total returns for TWCUX through July 2026, from SEC filings.
| Period | Total return |
|---|---|
| YTD | 1.65% |
| 1 year | 9.30% |
| 3 years (annualised) | 16.19% |
| 5 years (annualised) | 8.64% |
TWCUX Risk Information
Risk metrics for TWCUX, derived from monthly returns in SEC filings.
- 1-year volatility (annualised): 18.18%
TWCUX Costs and Fees
TWCUX costs about $87 per $10,000 invested per year in fund expenses.
- Net expense ratio: 0.87%
- Gross expense ratio: 0.87%
- Portfolio turnover: 15%
- Brokerage commissions: 0.43 bps of average net assets (SEC N-CEN)
TWCUX Cashflows
Over the 12 months to 2026-07, Ultra Fund had net outflows of $213.08M, from monthly SEC N-PORT filings.
| Month | Net flow |
|---|---|
| 2026-07 | −$179.32M |
| 2026-06 | −$196.65M |
| 2026-05 | −$200.60M |
| 2026-04 | −$147.08M |
| 2026-03 | −$200.91M |
| 2026-02 | −$167.81M |
TWCUX Debt Constituents
No individual debt constituents are reported in Ultra Fund's latest SEC N-PORT filing.
TWCUX Prospectus and SEC Filings
Official Ultra Fund filings on SEC EDGAR — prospectus, portfolio holdings and annual reports.
- Prospectus (485BPOS) — filed 2026-02-27
- Prospectus (497) — filed 2026-07-31
- Prospectus (497) — filed 2025-07-31
- Portfolio holdings (N-PORT) — filed 2026-09-29
- Portfolio holdings (N-PORT) — filed 2026-06-26
- Portfolio holdings (N-PORT) — filed 2026-03-30
- Annual census (N-CEN) — filed 2026-01-14
- Annual census (N-CEN) — filed 2025-01-08
TWCUX Service Providers
Firms that manage, distribute, hold, administer and audit Ultra Fund, as reported on SEC Form N-CEN, fiscal year ending October 31, 2025.
- Adviser: American Century Investment Management, Inc.
- Distributor: American Century Investment Services, Inc.
- Custodian: State Street Bank and Trust Company
- Transfer agent: American Century Services, LLC
- Administrator: American Century Services, LLC
- Auditor: Deloitte and Touche LLP
- Securities lending agent: State Street Bank and Trust Company
Related Funds
Other Trading - Leveraged funds tracked on ABC INVEST:
TWCUX: Frequently Asked Questions
What is the expense ratio of Ultra Fund (TWCUX)?
TWCUX has a net expense ratio of 0.87%, about $87 a year for every $10,000 invested. TWCUX fees and costs
Does TWCUX charge a sales load?
No. This share class (TWCUX) charges no sales load.
What is the minimum investment for TWCUX?
The minimum initial investment in TWCUX is $2,500, and additional purchases must be at least $50. For IRAs the minimum is $1,000. With an automatic investment plan it is $500. The fund may waive or reduce these minimums. Source: the fund's summary prospectus (July 2026).
What are TWCUX's top holdings?
As of July 31, 2026, TWCUX held 65 positions. The largest are NVIDIA Corp (16.05%), Alphabet Inc (6.37%), Microsoft Corp (6.26%), Amazon.com Inc (5.93%) and Apple Inc (5.91%). All TWCUX holdings
Can I download the full list of TWCUX holdings?
Yes. The complete TWCUX holdings list as of July 31, 2026 can be downloaded as a CSV file from the Holdings page: holding, ticker, FIGI, sector, country, asset type, shares, value and share of net assets, from the fund's SEC N-PORT filing. Download TWCUX holdings (CSV)
How has Ultra Fund performed?
TWCUX returned +9.3% over the 12 months to July 2026, +16.2% a year over 3 years and +8.6% a year over 5 years. TWCUX performance and risk
How large is TWCUX?
TWCUX manages $25.79B (SEC N-PORT, July 2026). Investors withdrew a net $213.08M over the past 12 months.
Who manages TWCUX and when did it launch?
TWCUX is managed by American Century Investment Management, Inc.. It is a series of American Century Mutual Funds, Inc.. It launched on November 2, 1981.
How does TWCUX compare with similar Trading - Leveraged funds?
Among 206 Trading - Leveraged funds with $100M+ in assets, TWCUX has the lowest net expense ratio (0.87%) and ranks #3 of 206 by assets. The largest is JPMorgan Ultra-Short Income ETF (JPST). Compare TWCUX with JPST
Where can I find TWCUX's prospectus and SEC filings?
TWCUX's latest prospectus (497) was filed July 31, 2026 and its latest N-PORT holdings report was filed September 29, 2026. All 60 filings are linked on ABC INVEST and on SEC EDGAR (series S000006195). TWCUX SEC filings
Data Sources
ABC INVEST compiles this page from public filings made to the U.S. Securities and Exchange Commission (SEC) through EDGAR: portfolio holdings and monthly cashflows from Form N-PORT, expenses and returns from fund prospectuses (Form 485BPOS) and the SEC DERA Risk/Return Summary data sets, and annual data from Form N-CEN.
For information only. Not investment advice: figures are as reported in SEC filings and may contain errors or be out of date. Past performance does not guarantee future results.