FIBUX Performance — Fidelity Flex U.S. Bond Index Fund
Data updated: 2026-07-24
FIBUX returned +0.58% year to date and +5.17% over one year to May 2026. Annualised returns are +3.96% over 3 years and +0.20% over 5 years. The fund trailed its Intermediate Core Bond category average: $100 invested three years ago grew to $112, against $115 for the category, and to $105 over one year, against $105. Volatility over the past three years was 5.54% a year. In the 12 months to May 2026 the fund took in a net $1.2B, and assets reached $4.03B.
FIBUX Growth of $100
What $100 invested in Fidelity Flex U.S. Bond Index Fund grew to, compounded from monthly returns reported on SEC Form N-PORT, against the Intermediate Core Bond category average over the same months.
| Period | FIBUX | Category average |
|---|---|---|
| 1 year (Jun 2025 – May 2026) | $105 | $105 |
| 3 years (Jun 2023 – May 2026) | $112 | $115 |
| 5 years (Jun 2021 – May 2026) | $101 | $103 |
| Since data start (Sep 2019 – May 2026) | $105 | $109 |
FIBUX Trailing Returns
Total returns to May 2026, from SEC N-PORT.
| Period | Total return |
|---|---|
| YTD | +0.58% |
| 1 year | +5.17% |
| 3 years (annualised) | +3.96% |
| 5 years (annualised) | +0.20% |
FIBUX Annual Returns
Calendar-year total returns of Fidelity Flex U.S. Bond Index Fund, compounded from monthly SEC N-PORT returns. Partial years show the months covered.
| Year | Total return |
|---|---|
| 2026 (Jan–May) | +0.58% |
| 2025 | +7.19% |
| 2024 | +1.31% |
| 2023 | +5.46% |
| 2022 | −12.96% |
| 2021 | −1.88% |
| 2020 | +7.72% |
| 2019 (Sep–Dec) | −0.52% |
FIBUX Monthly Returns
Monthly total returns as reported on SEC Form N-PORT.
| Year | Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 2026 | +0.2% | +1.7% | −1.8% | +0.1% | +0.4% | — | — | — | — | — | — | — |
| 2025 | +0.7% | +2.2% | 0.0% | +0.3% | −0.7% | +1.5% | −0.3% | +1.2% | +1.1% | +0.7% | +0.7% | −0.4% |
| 2024 | −0.1% | −1.5% | +0.9% | −2.5% | +1.7% | +1.0% | +2.3% | +1.4% | +1.4% | −2.5% | +1.1% | −1.7% |
| 2023 | +3.1% | −2.6% | +2.6% | +0.7% | −1.2% | −0.3% | −0.1% | −0.6% | −2.5% | −1.6% | +4.5% | +3.7% |
| 2022 | −2.0% | −1.1% | −2.7% | −3.8% | +0.6% | −1.5% | +2.4% | −2.8% | −4.3% | −1.3% | +3.6% | −0.6% |
| 2021 | −0.8% | −1.6% | −1.3% | +0.9% | +0.1% | +0.9% | +1.1% | −0.2% | −0.8% | −0.1% | +0.2% | −0.3% |
| 2020 | +2.1% | +1.7% | −0.3% | +1.7% | +0.5% | +0.6% | +1.4% | −0.9% | 0.0% | −0.5% | +1.1% | +0.1% |
| 2019 | — | — | — | — | — | — | — | — | −0.5% | +0.2% | 0.0% | −0.2% |
FIBUX Risk
Risk measures from monthly returns over Jun 2023 – May 2026.
- 3-year volatility (annualised): 5.54%
- 3-year Sharpe ratio: -0.10 (vs 4.5% risk-free rate)
- Best month: +4.51% (Nov 2023)
- Worst month: −2.54% (Sep 2023)
FIBUX Fund Flows
Monthly money in and out of Fidelity Flex U.S. Bond Index Fund, from SEC Form N-PORT.
- 12-month net flow: $1.2B
- 12-month gross sales (incl. reinvestments): $1.8B
- Sales ÷ redemptions: 2.74×
| Month | Sales | Redemptions | Net flow |
|---|---|---|---|
| May 2026 | $245.0M | $63.3M | $181.7M |
| Apr 2026 | $169.7M | $71.3M | $98.4M |
| Mar 2026 | $142.9M | $79.3M | $63.6M |
| Feb 2026 | $162.2M | $52.9M | $109.4M |
| Jan 2026 | $172.2M | $59.0M | $113.2M |
| Dec 2025 | $150.1M | $54.8M | $95.2M |
| Nov 2025 | $116.7M | $47.7M | $68.9M |
| Oct 2025 | $133.0M | $52.6M | $80.4M |
| Sep 2025 | $134.7M | $49.5M | $85.2M |
| Aug 2025 | $129.8M | $47.1M | $82.7M |
| Jul 2025 | $147.8M | $54.3M | $93.4M |
| Jun 2025 | $142.3M | $41.4M | $100.9M |
FIBUX Assets Under Management
Net assets of Fidelity Flex U.S. Bond Index Fund by report date, from SEC N-PORT filings.
| Report date | Net assets |
|---|---|
| 2026-05-31 | $4.03B |
| 2026-02-28 | $3.77B |
| 2025-11-30 | $3.43B |
| 2025-08-31 | $3.16B |
| 2025-05-31 | $2.83B |
| 2025-02-28 | $2.77B |
| 2024-11-30 | $2.55B |
| 2024-08-31 | $2.40B |
| 2024-05-31 | $2.18B |
| 2024-02-29 | $1.97B |
| 2023-11-30 | $1.77B |
| 2023-08-31 | $1.71B |
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.