MSTZX Performance — MassMutual Short-Duration Bond Fund, Class I
Data updated: 2026-08-27
MSTZX returned +1.25% year to date and +3.90% over one year to Jun 2026. Annualised returns are +6.59% over 3 years and +2.33% over 5 years. The fund trailed its Short-Term Corporate Bond category average: $100 invested three years ago grew to $121, against $121 for the category, and to $104 over one year, against $105. Volatility over the past three years was 1.67% a year. In the 12 months to Jun 2026 the fund lost a net $19.5M, and assets reached $125.93M.
MSTZX Growth of $100
What $100 invested in MassMutual Short-Duration Bond Fund grew to, compounded from monthly returns reported on SEC Form N-PORT, against the Short-Term Corporate Bond category average over the same months.
| Period | MSTZX | Category average |
|---|---|---|
| 1 year (Jul 2025 – Jun 2026) | $104 | $105 |
| 3 years (Jul 2023 – Jun 2026) | $121 | $121 |
| 5 years (Jul 2021 – Jun 2026) | $112 | $117 |
| Since data start (Jul 2019 – Jun 2026) | $120 | $128 |
MSTZX Trailing Returns
Total returns to Jun 2026, from SEC N-PORT.
| Period | Total return |
|---|---|
| YTD | +1.25% |
| 1 year | +3.90% |
| 3 years (annualised) | +6.59% |
| 5 years (annualised) | +2.33% |
MSTZX Annual Returns
Calendar-year total returns of MassMutual Short-Duration Bond Fund, compounded from monthly SEC N-PORT returns. Partial years show the months covered.
| Year | Total return |
|---|---|
| 2026 (Jan–Jun) | +1.25% |
| 2025 | +6.03% |
| 2024 | +7.88% |
| 2023 | +7.08% |
| 2022 | −9.38% |
| 2021 | +2.05% |
| 2020 | +2.41% |
| 2019 (Jul–Dec) | +1.83% |
MSTZX 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 | +0.7% | +0.2% | −0.5% | +0.6% | +0.1% | +0.2% | — | — | — | — | — | — |
| 2025 | +0.4% | +0.8% | +0.6% | +0.5% | +0.3% | +0.8% | +0.4% | +0.9% | +0.5% | +0.4% | +0.1% | +0.4% |
| 2024 | +0.7% | 0.0% | +1.1% | +0.7% | +1.0% | 0.0% | +1.1% | +1.0% | +1.4% | +0.4% | +0.5% | −0.3% |
| 2023 | −1.1% | +0.4% | +2.2% | −0.1% | +0.7% | +0.3% | +0.1% | +0.4% | +0.8% | +1.6% | +1.7% | 0.0% |
| 2022 | −2.5% | −1.8% | −1.1% | −1.7% | −0.2% | −1.4% | −1.7% | +0.1% | +0.4% | +1.0% | +0.4% | −1.2% |
| 2021 | +0.2% | +0.4% | +0.8% | +0.2% | +0.3% | +0.3% | +0.1% | +0.2% | +0.1% | −0.2% | −0.3% | −0.1% |
| 2020 | −7.0% | 0.0% | +0.3% | +2.6% | +1.1% | +0.6% | +0.7% | +1.1% | +1.3% | +0.7% | +0.9% | +0.4% |
| 2019 | — | — | — | — | — | — | +0.3% | +0.3% | +0.4% | +0.3% | +0.3% | +0.3% |
MSTZX Risk
Risk measures from monthly returns over Jul 2023 – Jun 2026.
- 3-year volatility (annualised): 1.67%
- 3-year Sharpe ratio: 1.25 (vs 4.5% risk-free rate)
- Best month: +1.70% (Nov 2023)
- Worst month: −0.50% (Mar 2026)
MSTZX Fund Flows
Monthly money in and out of MassMutual Short-Duration Bond Fund, from SEC Form N-PORT.
- 12-month net flow: −$19.5M
- 12-month gross sales (incl. reinvestments): $77.2M
- Sales ÷ redemptions: 0.80×
| Month | Sales | Redemptions | Net flow |
|---|---|---|---|
| Jun 2026 | $6.5M | $11.2M | −$4.7M |
| May 2026 | $8.4M | $4.9M | $3.6M |
| Apr 2026 | $4.5M | $3.7M | $769K |
| Mar 2026 | $7.2M | $4.1M | $3.1M |
| Feb 2026 | $7.9M | $9.3M | −$1.4M |
| Jan 2026 | $6.3M | $6.3M | −$85K |
| Dec 2025 | $9.9M | $4.1M | $5.8M |
| Nov 2025 | $4.5M | $5.4M | −$908K |
| Oct 2025 | $7.9M | $2.6M | $5.3M |
| Sep 2025 | $4.4M | $25.3M | −$20.9M |
| Aug 2025 | $6.1M | $13.0M | −$6.9M |
| Jul 2025 | $3.7M | $6.8M | −$3.1M |
MSTZX Assets Under Management
Net assets of MassMutual Short-Duration Bond Fund by report date, from SEC N-PORT filings.
| Report date | Net assets |
|---|---|
| 2026-06-30 | $125.93M |
| 2026-03-31 | $126.63M |
| 2025-12-31 | $125.87M |
| 2025-09-30 | $116.02M |
| 2025-06-30 | $146.04M |
| 2025-03-31 | $148.80M |
| 2024-12-31 | $152.86M |
| 2024-09-30 | $157.09M |
| 2024-06-30 | $167.09M |
| 2024-03-31 | $173.65M |
| 2023-12-31 | $175.45M |
| 2023-09-30 | $212.98M |
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.