The Tool Desk
Outbyte Driver Updater FREEFix the driver behind crashes, sound loss and screen glitchesFind Drivers →Outbyte PC Repair FREERepair Windows errors before they cause bigger problemsFix Now →Mortgage-backed securities (MBS) ETFs can lose value when interest rates rise because the bonds they own usually decline in price as market yields increase. MBS add a second, distinctive risk: homeowners can repay their mortgages early. Falling rates can accelerate those repayments, returning principal before investors expected it and forcing the fund to reinvest at lower yields. Rising rates can slow repayments, extending the expected life of the mortgages and making the portfolio more sensitive to additional rate increases. The result is that an MBS ETF may perform differently from a conventional bond fund in both rising- and falling-rate markets.
The ordinary bond effect comes first
A mortgage-backed security is still a fixed-income investment. Its market value reflects the present value of expected future principal and interest payments. When newly issued bonds offer higher yields, older bonds with lower coupons generally become less attractive, so their prices fall until their yields are competitive. When market yields decline, existing bonds generally become more valuable.
As an Amazon Associate I earn from qualifying purchases.
This relationship applies to the bonds inside an ETF. The fund’s net asset value (NAV) changes as dealers and pricing services revalue those holdings, and the ETF’s exchange-traded share price usually follows. The size of the move depends heavily on the portfolio’s interest-rate sensitivity, commonly expressed as effective duration.
What’s actually slowing this PC down?
Pick the symptom - the matching free tool is one click away.
Duration is a sensitivity estimate, not a promise
Duration approximates the percentage change in a bond or portfolio’s price for a one-percentage-point change in yields, assuming other conditions remain constant. A portfolio with a duration of five years would have an estimated 5% price decline if yields rose one percentage point, before considering income, convexity, credit changes, trading effects or other factors.
#1 Best Overall
- Compact & Portable Design: This Small Excel, Word, PowerPoint, & Windows Cheat Sheet Mouse Pad measures 11.8" x 9.8", offering a portable mouse pad. Its compact size fits in bags or laptop cases, suitable for professionals, students, or travelers.
- Multi-Software Shortcut Guide: Featuring essential shortcut keys for Excel, Word, PowerPoint, & Windows, this small mouse pad provides a quick reference for frequently used shortcuts, offering a reference designed to support workflow efficiency
- Smooth & Precise Surface: The finely-textured surface ensures precise mouse control, allowing for smooth and accurate movement during work or gaming sessions.
- Durable & Non-Slip Design: This Multi-Software Shortcut Mouse Pad features stitched edges to reduce fraying. The non-slip rubber base helps keep it securely in place, and the water-resistant fabric allows for easier maintenance.
- Clear Print Quality: Displays high-resolution printing intended to remain legible through regular use and cleaning
One SEC-filed fund illustration uses a hypothetical ten-year portfolio duration: a one-percentage-point rate increase would imply an approximately 10% decrease in value, all else equal. That example is not a forecast for an MBS ETF. Actual duration changes over time, and mortgage prepayments make the calculation more complex than the duration of a plain, non-callable bond.
Why mortgages behave differently from ordinary bonds
An MBS represents claims on payments from a pool of home loans. Investors receive scheduled interest and principal, but the timing of principal repayment is uncertain because borrowers can refinance, sell their homes or otherwise pay their loans off early. This borrower-controlled repayment feature is often called a prepayment option.
As interest rates move, the option changes the cash-flow schedule that investors are valuing. The fund is therefore exposed not only to the direction of rates, but also to how quickly homeowners respond to those rates.
Recommended Free Tools
When rates fall: faster prepayments create reinvestment risk
Suppose mortgage rates decline. Homeowners with older, higher-rate loans have more incentive to refinance into cheaper mortgages. More loans in the MBS pool may then be paid off earlier than projected.
Rank #2
- [MULTIFUNCTIONAL]You'll get 2 pieces computer monitor memo boards that you can stick on the left and right edges of your monitor, and they're the perfect office desk organizers and accessories. Computer monitor side panels desktop organizer are suitable for home work or office,bringing convenience. Desktop memo is used to organize meeting memos, important messages, business cards, planning notes.Paste on the message board to keep track of important things and to-do items to prevent forgetting.
- [🌟HIGHLY QUALITY] The material of computer screen side note holder is transparent acrylic. Durable, simple, stylish, light weight, easy to use, not easy to fall off or break. This cute office supplies for women desk can be used for a long time. This computer desk accessories is waterproof and dirt resistance, and look simple and stylish. The transparent acrylic sticky note holder as cubicle accessories is easy to notice the context of your sticky notes.
- [📋Easy to use] Office must haves cool office gadgets for desk ready to tear, easy to install and remove, not easy to leave traces. You only need to peel off the protective film on the surface of the computer side board memo, wipe off the dust on the edge of the computer monitor, and then stick the desk essentials for women office on the right or left side of the tape, and you're done. A perfect gift for your colleagues, friends or classmates and family members or relatives
- [🏢MULTI-SCENE USE] This desk supplies computer memo board can be applied to home and office, clear your office decor for women, suitable for most computer monitors, screens and cabinets, you can put it where you think, this cute office decor serve as a reminder. Stick on the computer side. It’s a good office gadgets can remind work improve office productivity. Pasted cabinets, dressers, refrigerators, walls, etc as cubicle accessories. To make life more orderly.
- [💌NOTE] The adhesive force of the computer sticky note holder is very strong. It can not be directly pasted on the computer screen. It should pasted on the black edge of the screen. Narrow edge not recommended!!! If you are not satisfied with your purchase, or if the product is damaged or broken in transit, please let us know immediately. We will promptly solve your problem.
Early principal repayment sounds beneficial, but it creates two problems for the ETF:
- Reinvestment risk: The fund receives principal sooner and must put it back to work when newly available bonds may offer lower yields. Future income can therefore fall.
- Limited price appreciation: Investors cannot keep receiving the old, higher-rate cash flows indefinitely when borrowers can refinance. The security’s value may rise less than that of a similar bond without a prepayment option.
This is why a falling-rate environment is not automatically a windfall for MBS investors. A conventional bond with fixed maturity dates may enjoy a larger price gain, while an MBS may return principal and lose its higher-coupon loans just as rates become less attractive.
When rates rise: slower prepayments create extension risk
If mortgage rates rise, refinancing becomes less appealing. Borrowers are more likely to keep their existing loans, so principal repayments can slow. The expected life of the MBS then lengthens: cash that investors expected to receive earlier may arrive years later.
This is extension risk. A longer expected life generally means a longer effective duration. The ETF can become more sensitive to another increase in rates at the same time that its existing holdings are already losing value from the initial increase.
Rank #3
- Stay Organized with Ease: Our To Do List Notepad provides multiple sections with plenty of space to jot down all of your important tasks.A versatile office supply perfect for daily task management, helping you keep track of everything that needs to be done and prioritize effectively.
- Achieve Your Productivity Goals: Begin each day on a positive note, reminding you of your potential, strength, and the significance of staying focused on your goals. Our Daily Checklist Notepad is the ultimate tool to streamline your daily planning and elevate your productivity. With a clear and concise overview of your tasks, you can effortlessly prioritize what truly matters and make consistent strides towards achieving your goals.
- Reliable and Stylish: Our to do list planner combines functionality with durability. With a transparent PP cover, the inner pages are well-protected from dirt and wear. Additionally, the back cover is crafted with thick paperboard, offering a stable surface for your writing needs. Each notepad includes 52 pages of high-quality, 100gsm paper, which is thick and non-bleeding, resulting in a smooth and enjoyable writing experience.
- Versatile Use: This daily checklist notepad, suitable for teacher supplies and a wide range of applications, proves invaluable in various settings including work, school, and home. Whether you need to organize your daily tasks, plan a project, or create a grocery list, this notepad serves as the ideal tool. Its compact size ensures easy portability, allowing you to conveniently carry it with you throughout your day.
- Perfect Present for Anyone: Our Daily To-Do List Notepad is the perfect present for those who value organization and productivity. With its stylish design and versatility, this office desk accessory is also a practical addition to school supplies. Suitable for students, professionals, and homemakers alike, it helps keep tasks and priorities in check effortlessly.
A current Vanguard fund prospectus summarizes the possibility this way: “During periods of rising interest rates, certain bonds held by the Fund may be paid off substantially more slowly than originally anticipated.” The statement describes a general MBS risk, not a guaranteed outcome for every fund or market episode.
How the two rate directions affect an MBS ETF
| Rate movement | Typical mortgage cash-flow response | Potential effect on value or income |
|---|---|---|
| Rates rise | Refinancing and prepayments may slow; expected life can extend. | Existing bond prices face ordinary rate pressure, while a longer effective duration can increase sensitivity to further rate increases. |
| Rates fall | Refinancing and prepayments may accelerate. | Principal may be returned early and reinvested at lower yields; early repayment can also limit price appreciation. |
These are tendencies, not mechanical rules. Borrower behavior, mortgage coupons, security structure, the pace and expected persistence of the rate move, credit conditions and ETF trading conditions can all change the result. The same one-percentage-point move will not produce a universal gain or loss across all MBS ETFs.
How those risks reach the ETF share price
NAV and exchange trading are related but not identical
An ETF calculates a NAV from the estimated market value of its holdings. Investors, however, buy and sell shares on an exchange. The market price can temporarily trade above or below NAV, particularly when the underlying mortgage market is less liquid or when markets move abruptly.
That means an investor’s result can include both the change in the securities’ underlying value and the premium or discount at which the ETF shares trade. Bid-ask spreads can add another cost when entering or exiting. A fund with liquid shares may still hold mortgage securities whose prices are harder to establish during stressed markets.
Rank #4
- 【Adjustable & Ergonomic】：This laptop stand can be adjusted to a comfortable height and angle according to your actual needs, letting you fix posture and reduce your neck fatigue, back pain and eye strain. Very comfortable for working in home, office and outdoor.
- 【Sturdy & Protective】 ：Made of sturdy metal, it can support up to 17.6 lbs (8kg) weight on top; With 2 rubber mats on the hook and anti-skid silicone pads on top & bottom, it can secure your laptop in place and maximum protect your device from scratches and sliding. Moreover, smooth edges will never hurt your hands.
- 【Heat Dissipation】 ：The top of the laptop stand is designed with multiple ventilation holes. The open design offers greater ventilation and more airflow to cool your laptop during operation other than it just lays flat on the table.
- 【Portable & Foldable】：The foldable design allows you to easily slip it in your backpack. Ideal for people who travel for business a lot.
- 【Broad Compatibility】：Our desktop book stand is compatible with all laptops from 10-15.6 inches, such as MacBook Air/ Pro, Google Pixelbook, Dell XPS, HP, ASUS, Lenovo ThinkPad, Acer, Chromebook and Microsoft Surface, etc.Be your ideal companion in Home, Office & Outdoor.
Portfolio duration is not fixed
Mortgage prepayments alter effective duration. When refinancing slows, the portfolio can extend; when refinancing speeds up, it can shorten. A duration figure shown on a fund website is therefore a measurement for a particular date and set of assumptions, not a permanent property.
Duration also does not capture every source of risk. Mortgage securities can show negative convexity: their sensitivity to rates changes as rates move. In a rally, faster prepayments can reduce the benefit of falling yields; in a sell-off, slower prepayments can increase exposure to rising yields.
Independent reader supportYour contribution helps us test, update, and keep practical guides available for everyone.Why two MBS ETFs can lose different amounts
“MBS ETF” describes a category, not a single risk profile. Before comparing funds, examine the characteristics that determine how each portfolio responds.
Quick wins for a faster PC:
Fix the driver behind crashes, sound loss and screen glitchesFind Drivers →Clear out junk files and repair common Windows errorsFree Scan →| Characteristic | Why it matters |
|---|---|
| Effective duration and its calculation | Indicates approximate rate sensitivity, but can change as prepayment assumptions change. |
| Agency versus non-agency exposure | Agency securities and non-agency securities have different credit and structural risks. Non-agency holdings can be more exposed to borrower credit performance. |
| Mortgage coupon and vintage | Loans originated in different rate environments can have different refinancing incentives and prepayment behavior. |
| Security mix | Different mortgage structures can produce different cash-flow timing and liquidity characteristics. |
| Active or index approach | An active manager may alter exposures; an index fund follows its index methodology and can experience tracking differences. |
| Liquidity and trading spread | Wider spreads or less liquid underlying securities can increase transaction costs and price deviations from NAV. |
| Market price relative to NAV | A premium or discount can affect the return an investor actually receives even when NAV is unchanged. |
Use the latest prospectus, holdings report and trading data for the particular ETF. Generic MBS risk language cannot supply a fund’s current duration, yield, composition or premium/discount.
Best Value
- Twin-Ball Design : Hiacry gel pen features a double ball conical tip that reduces writing resistance and provides a stable and smooth writing experience. 0.7mm quick drying black ink ensures no jumping, leakage or seepage.
- Quick-Dry Long Lasting Ink：0.7mm black ink can slide effortlessly, dry immediately, & is not easily dirty. It has a high-capacity reservoir (up to 1300 meters), which is very suitable for left-handed & right-handed users.
- Sleek Design for Journaling & Planning: Engineered with a low center of gravity and precision tip for steady ink flow, these journaling pens excel at note-taking, sketching, planning, and more. They combine stylish pens with top-tier performance.
- Rolling Ball Design：The pocket clip with roll ball design can be easily attached to notebook pockets and binders, in addition, the fidget on the pen clip is also a small toy for your daily thinking to relieve stress.
- Comfortable Non-Slip Grip：The ergonomic pen barrel has a soft rubberized coating for a comfortable, non-slip grip, so you won't get fatigued even after long hours of writing.
Three rate scenarios in plain numbers
A rapid one-percentage-point increase
Imagine, only as an illustration, an ETF whose effective duration is ten years at the start of a rate shock. A one-percentage-point increase in relevant yields could imply roughly a 10% decline in the portfolio’s value before income and other effects. If higher rates also slow prepayments, the duration could extend, increasing sensitivity to another move. The illustration does not predict the ETF’s actual return.
A gradual decline in mortgage rates
Lower rates can lift the market value of existing mortgages initially. As more homeowners refinance, however, principal comes back earlier. The ETF then replaces higher-coupon mortgages with securities issued at lower yields, reducing future income. The price gain may also be smaller than an investor would expect from a non-callable bond with similar duration.
Fast, volatile rate swings
When rates move sharply in both directions, prepayment models can change repeatedly. Dealers may widen spreads, and the ETF’s market price can move differently from its end-of-day NAV. Investors who trade during a stressed session may realize a result that reflects liquidity and execution as well as the underlying bond move.
Other forces that can make the ETF fall
Credit risk
Some MBS are backed by government-sponsored or government-agency programs, while others rely more directly on the ability of private borrowers or issuers to pay. Deteriorating housing or borrower credit conditions can reduce values independently of Treasury yields. Check the fund’s eligibility rules and actual holdings rather than assuming every MBS ETF has the same guarantee or credit profile.
Liquidity risk
Mortgage markets can become harder to trade during periods of stress. If dealers quote wider spreads or fewer buyers are available, estimated prices and ETF trading prices can both become more volatile. Liquidity risk can magnify a rate-driven move but is a separate mechanism from duration.
Tracking and portfolio-management risk
An index ETF can underperform its index because of fees, transaction costs, sampling and rebalancing. An actively managed ETF can differ from broad MBS benchmarks because the manager changes security, coupon or maturity exposures. Those differences can help or hurt in a particular rate cycle.
A practical checklist before buying or selling
- Read the current prospectus. Identify the fund’s stated interest-rate, prepayment, extension, credit and liquidity risks.
- Check effective duration. Note the date, methodology and whether the figure is portfolio-level or limited to a particular sleeve.
- Inspect holdings. Review agency and non-agency allocations, mortgage coupons, maturities, concentrations and security types.
- Look at recent duration history. A changing duration can reveal whether prepayments or portfolio changes are altering rate exposure.
- Review NAV premiums and discounts. Compare the exchange price with NAV, especially around volatile sessions.
- Check trading spreads and volume. Use limit orders when appropriate and understand that a liquid ticker does not guarantee identical liquidity in every underlying mortgage.
- Match the fund to your time horizon. Extension risk can be especially uncomfortable for investors who may need the money during a rising-rate period.
Common misconceptions
- “Rates fell, so every bond fund should rise.” Prepayments can return higher-coupon mortgage principal early and cap the MBS price response.
- “An MBS ETF has one permanent duration.” Effective duration changes as borrower refinancing behavior changes.
- “A duration estimate tells me the exact loss.” It is an approximation that assumes other variables remain constant and does not fully capture convexity, credit, liquidity or trading-price effects.
- “All mortgage ETFs are interchangeable.” Agency exposure, credit risk, coupon, vintage, structure, management approach and liquidity can produce materially different outcomes.
How to interpret a loss on your statement
Start by separating the sources. Compare the ETF’s market-price return with its NAV return for the same period, then review the distribution you received. A market-price decline larger than the NAV decline can indicate a widening discount or trading effect. A NAV decline during rising rates is consistent with duration and extension pressure, while a smaller-than-expected gain during falling rates can reflect faster prepayments and reinvestment at lower yields.
Free tools Windows power users keep installed
One-click scans. No signup required.
This decomposition does not predict what will happen next. It helps identify whether the observed move came mainly from broad rate sensitivity, changing mortgage cash flows, credit conditions or the ETF’s exchange trading.
Quick Recap
Product prices and availability are accurate as of the date/time indicated and are subject to change. Any price and availability information displayed on Amazon at the time of purchase will apply.
