What Is an Adjustable-Rate Mortgage (ARM)?

The term adjustable-rate mortgage (ARM) refers to a home loan with a variable interest rate. With an ARM, the initial interest rate is fixed for a period of time. After that, the interest rate applied on the outstanding balance resets periodically, at yearly or even monthly intervals.

ARMs are also called variable-rate mortgages or floating mortgages. The interest rate for ARMs is reset based on a benchmark or index, plus an additional spread called an ARM margin. The typical index that is used in ARMs has been the London Interbank Offered Rate (LIBOR).

Understanding Adjustable-Rate Mortgages (ARMs)

Mortgages allow homeowners to finance the purchase of a home or other piece of property. When you get a mortgage, you’ll need to repay the borrowed sum over a set number of years as well as pay the lender something extra to compensate them for their troubles and the likelihood that inflation will erode the value of the balance by the time the funds are reimbursed.

In most cases, you can choose the type of mortgage loan that best suits your needs. A fixed-rate mortgage comes with a fixed interest rate for the entirety of the loan. As such, your payments remain the same. An ARM, where the rate fluctuates based on market conditions. This means that you benefit from falling rates and also run the risk if rates increase.

There are two different periods to an ARM. One is the fixed period and the other is the adjusted period. Here’s how the two differ:

• Fixed Period: The interest rate doesn’t change during this period. It can range anywhere between the first five, seven, or 10 years of the loan. This is commonly known as the intro or teaser rate.
• Adjusted Period: This is the point at which the rate changes. Changes are made during this period based on the underlying benchmark, which fluctuates based on market conditions.

Another key characteristic of ARMs is whether they are conforming or nonconforming loans. Conforming loans are those that meet the standards of government-sponsored enterprises (GSEs) like Fannie Mae and Freddie Mac. They are packaged and sold off on the secondary market to investors. Nonconforming loans, on the other hand, aren’t up to the standards of these entities and aren’t sold as investments.

Rates are capped on ARMs. This means that there are limits on the highest possible rate a borrower must pay. Keep in mind, though, that your credit score plays an important role in determining how much you’ll pay. So, the better your score, the lower your rate.

Types of ARMs

ARMs generally come in three forms: Hybrid, interest-only (IO), and payment option. Here’s a quick breakdown of each.

Hybrid ARM

Hybrid ARMs offer a mix of a fixed- and adjustable-rate period. With this type of loan, the interest rate will be fixed at the beginning and then begin to float at a predetermined time.

This information is typically expressed in two numbers. In most cases, the first number indicates the length of time that the fixed rate is applied to the loan, while the second refers to the duration or adjustment frequency of the variable rate.

For example, a 2/28 ARM features a fixed rate for two years followed by a floating rate for the remaining 28 years. In comparison, a 5/1 ARM has a fixed rate for the first five years, followed by a variable rate that adjusts every year (as indicated by the number one after the slash). Likewise, a 5/5 ARM would start with a fixed rate for five years and then adjust every five years.

Interest-Only (I-O) ARM

It’s also possible to secure an interest-only (I-O) ARM, which essentially would mean only paying interest on the mortgage for a specific time frame—typically three to 10 years. Once this period expires, you are then required to pay both interest and the principal on the loan.

These types of plans appeal to those keen to spend less on their mortgage in the first few years so that they can free up funds for something else, such as purchasing furniture for their new home. Of course, this advantage comes at a cost: The longer the I-O period, the higher your payments will be when it ends.

Payment-Option ARM

A payment-option ARM is, as the name implies, an ARM with several payment options. These options typically include payments covering principal and interest, paying down just the interest, or paying a minimum amount that does not even cover the interest.

Opting to pay the minimum amount or just the interest might sound appealing. However, it’s worth remembering that you will have to pay the lender back everything by the date specified in the contract and that interest charges are higher when the principal isn’t getting paid off. If you persist with paying off little, then you’ll find your debt keeps growing—perhaps to unmanageable levels.

Advantages and Disadvantages of ARMs

Adjustable-rate mortgages come with many benefits and drawbacks. We’ve listed some of the most common ones below.

Advantages

The most obvious advantage is that a low rate, especially the intro or teaser rate, will save you money. Not only will your monthly payment be lower than most traditional fixed-rate mortgages, you may also be able to put more down toward your principal balance. Just ensure your lender doesn’t charge you a prepayment fee if you do.

ARMs are great for people who want to finance a short-term purchase, such as a starter home. Or you may want to borrow using an ARM to finance the purchase of a home that you intend to flip. This allows you to pay lower monthly payments until you decide to sell again.

More money in your pocket with an ARM also means you have more in your pocket to put toward savings or other goals, such as a vacation or a new car.

Unlike fixed-rate borrowers, you won’t have to make a trip to the bank or your lender to refinance when interest rates drop. That’s because you’re probably already getting the best deal available.

Disadvantages

One of the major cons of ARMs is that the interest rate will change. This means that if market conditions lead to a rate hike, you’ll end up spending more on your monthly mortgage payment. And that can put a dent in your monthly budget.

ARMs may offer you flexibility but they don’t provide you with any predictability as fixed-rate loans do. Borrowers with fixed-rate loans know what their payments will be throughout the life of the loan because the interest rate never changes. But because the rate changes with ARMs, you’ll have to keep juggling your budget with every rate change.

These mortgages can often be very complicated to understand, even for the most seasoned borrower. There are various features that come with these loans that you should be aware of before you sign your mortgage contracts, such as caps, indexes, and margins.

How the Variable Rate on ARMs Is Determined

At the end of the initial fixed-rate period, ARM interest rates will become variable (adjustable) and will fluctuate based on some reference interest rate (the ARM index) plus a set amount of interest above that index rate (the ARM margin). The ARM index is often a benchmark rate such as the prime rate, the LIBOR, the Secured Overnight Financing Rate (SOFR), or the rate on short-term U.S. Treasuries.

Although the index rate can change, the margin stays the same. For example, if the index is 5% and the margin is 2%, the interest rate on the mortgage adjusts to 7%. However, if the index is at only 2% the next time that the interest rate adjusts, the rate falls to 4% based on the loan’s 2% margin.

Adjustable-Rate Mortgage vs. Fixed Interest Mortgage

Unlike ARMs, traditional or fixed-rate mortgages carry the same interest rate for the life of the loan, which might be 10, 20, 30, or more years. They generally have higher interest rates at the outset than ARMs, which can make ARMs more attractive and affordable, at least in the short term. However, fixed-rate loans provide the assurance that the borrower’s rate will never shoot up to a point where loan payments may become unmanageable.

With a fixed-rate mortgage, monthly payments remain the same, although the amounts that go to pay interest or principal will change over time, according to the loan’s amortization schedule.

If interest rates in general fall, then homeowners with fixed-rate mortgages can refinance, paying off their old loan with one at a new, lower rate.

Is an ARM Right for You?

An ARM can be a smart financial choice if you are planning to keep the loan for a limited period of time and will be able to handle any rate increases in the meantime. Put simply, an adjustable-rate mortgage is well suited for the following types of borrowers:

• People who intend to hold the loan for a short period of time
• Individuals who expect to see a positive change in their income
• Anyone who can and will pay off the mortgage within a short time frame

In many cases, ARMs come with rate caps that limit how much the rate can rise at any given time or in total. Periodic rate caps limit how much the interest rate can change from one year to the next, while lifetime rate caps set limits on how much the interest rate can increase over the life of the loan.

Notably, some ARMs have payment caps that limit how much the monthly mortgage payment can increase, in dollar terms. That can lead to a problem called negative amortization if your monthly payments aren’t sufficient to cover the interest rate that your lender is changing. With negative amortization, the amount that you owe can continue to increase, even as you make the required monthly payments.

The Bottom Line

Borrowers have many options available to them when they want to finance the purchase of their home or another type of property. You can choose between a fixed-rate or adjustable-rate mortgage. While the former provides you with some predictability, ARMs offer lower interest rates for a certain period of time before they begin to fluctuate with market conditions. There are different types of ARMs to choose from and they have pros and cons. But keep in mind that these kinds of loans are better suited for certain kinds of borrowers, including those who intend to hold onto a property for the short term or if they intend to pay off the loan before the adjusted period begins. If you’re unsure, talk to a financial expert about your options.

What Is an American Option?

An American option, aka an American-style option, is a version of an options contract that allows holders to exercise the option rights at any time before and including the day of expiration. It contrasts with another type of option, called the European option, that only allows execution on the day of expiration.

An American-style option allows investors to capture profit as soon as the stock price moves favorably, and to take advantage of dividend announcements as well.

How American Options Work

American options outline the timeframe when the option holder can exercise their option contract rights. These rights allow the holder to buy or sell—depending on if the option is a call or put—the underlying asset, at the set strike price on or before the predetermined expiration date. Since investors have the freedom to exercise their options at any point during the life of the contract, American-style options are more valuable than the limited European options. However, the ability to exercise early carries an added premium or cost.

The last day to exercise a weekly American option is normally on the Friday of the week in which the option contract expires. Conversely, the last day to exercise a monthly American option is normally the third Friday of the month.

The majority of exchange-traded options on single stocks are American, while options on indexes tend to be European style.

American Call and Put Options

A long call option gives the holder the right to demand delivery of the underlying security or stock on any day within the contract period. This feature includes any day leading up to and the day of expiration. As with all options, the buyer does not have an obligation to receive the shares and is not required to exercise their right. The strike price remains the same specified value throughout the contract.

If an investor purchased a call option for a company in March with an expiration date at the end of December of the same year, they would have the right to exercise the call option at any time up until its expiration date.

American put options also allow the execution at any point up to and including the expiration date. This ability gives the buyer the freedom to demand the seller takes delivery of the underlying asset whenever the price falls below the specified strike price.

One reason for the early exercise has to do with the cost of carry or the opportunity cost associated with not investing the gains from the put option. When a put is exercised, investors are paid the strike price immediately. As a result, the proceeds can be invested in another security to earn interest.

However, the drawback to exercising puts is that the investor would miss out on any dividends since exercising would sell the shares. Also, the option itself might continue to increase in value if held to expiry, and exercising early might lead to missing out on any further gains.

When to Exercise Early

In many instances, holders of American-style options do not utilize the early exercise provision, since it’s usually more cost-effective to either hold the contract until expiration or exit the position by selling the option contract outright. In other words, as a stock price rises, the value of a call option increases, as does its premium. Traders can sell an option back to the options market if the current premium is higher than the initial premium paid at the onset. The trader would earn the net difference between the two premiums minus any fees or commissions from the broker.

However, there are times when options are typically exercised early. Deep-in-the-money call options—where the asset’s price is well above the option’s strike price—will usually be exercised early. Puts can also be deep-in-the-money when the price is significantly below the strike price. In most cases, deep prices are those that are more than $10 in-the-money. With lower-priced equities, deep-in-the-money might be characterized as a $5 spread between the strike price and market price.

Early execution can also happen leading up to the date a stock goes ex-dividend—the cutoff date by which shareholders must own the stock to receive the next scheduled dividend payment. Option holders do not receive dividend payments. So, many investors will exercise their options before the ex-dividend date to capture the gains from a profitable position and get paid the dividend.

Advantages and Disadvantages of American Options

American options are helpful since investors don’t have to wait to exercise the option when the asset’s price rises above the strike price. However, American-style options carry a premium—an upfront cost—that investors pay and which must be factored into the overall profitability of the trade.

Examples of an American Option

Say an investor purchased an American-style call option for Apple Inc. (AAPL) in March with an expiration date at the end of December in the same year. The premium is $5 per option contract—one contract is 100 shares ($5 x 100 = $500)—and the strike price on the option is $100. Following the purchase, the stock price rose to $150 per share.

The investor exercises the call option on Apple before expiration buying 100 shares of Apple for $100 per share. In other words, the investor would be long 100 shares of Apple at the $100 strike price. The investor immediately sells the shares for the current market price of $150 and pockets the $50 per share profit. The investor earned $5,000 in total minus the premium of $500 for buying the option and any broker commission.

Let’s say an investor believes shares of Meta Inc. (META), formerly Facebook, will decline in the upcoming months. The investor purchases an American-style July put option in January, which expires in September of the same year. The option premium is $3 per contract (100 x $3 = $300) and the strike price is $150.

Meta’s stock price falls to $90 per share, and the investor exercises the put option and is short 100 shares of Meta at the $150 strike price. The transaction effectively has the investor buying 100 shares of Meta at the current $90 price and immediately selling those shares at the $150 strike price. However, in practice, the net difference is settled, and the investor earns a $60 profit on the option contract, which equates to $6,000 minus the premium of $300 and any broker commissions.

Investopedia does not provide tax, investment, or financial services and advice. The information is presented without consideration of the investment objectives, risk tolerance, or financial circumstances of any specific investor and might not be suitable for all investors. Investing involves risk, including the possible loss of principal.

What Is the Annual Equivalent Rate (AER)?

The annual equivalent rate (AER) is the interest rate for a savings account or investment product that has more than one compounding period. AER is calculated under the assumption that any interest paid is included in the principal payment’s balance and the next interest payment will be based on the slightly higher account balance.

The AER method means that interest can be compounded several times in a year, depending on the number of times that interest payments are made.

AER is also known as the effective annual interest rate or the annual percentage yield (APY).

The AER is the actual interest rate that an investor will earn for an investment, a loan, or another product, based on compounding. The AER reveals to investors what they can expect to return from an investment (the ROI)—the actual return of the investment based on compounding, which is more than the stated, or nominal, interest rate.

Assuming that interest is calculated—or compounded—more than once a year, the AER will be higher than the stated interest rate. The more compounding periods, the greater the difference between the two will be.

Formula for the AER


$\begin{aligned} &\text{Annual equivalent rate}=\left(1 + \frac{r}{n}\right)^n-1\\ &\textbf{where:}\\ &n=\text{The number of compounding periods (times per year interest is paid)}\\ &r = \text{The stated interest rate}\\ \end{aligned}$​Annual equivalent rate=(1+nr​)n−1where:n=The number of compounding periods (times per year interest is paid)r=The stated interest rate​

How to Calculate the AER

To calculate AER:

1. Divide the stated interest rate by the number of times a year that interest is paid (compounded) and add one.
2. Raise the result to the number of times a year that interest is paid (compounded)
3. Subtract one from the subsequent result.

The AER is displayed as a percentage (%).

Example of AER

Let’s look at AER in both savings accounts and bonds.

For a Savings Account

Assume an investor wishes to sell all the securities in their investment portfolio and place all the proceeds in a savings account. The investor is deciding between placing the proceeds in Bank A, Bank B, or Bank C, depending on the highest rate offered. Bank A has a quoted interest rate of 3.7% that pays interest on an annual basis. Bank B has a quoted interest rate of 3.65% that pays interest quarterly, and Bank C has a quoted interest rate of 3.7% that pays interest semi-annually.

Therefore, Bank A would have an annual equivalent rate of 3.7%, or (1 + (0.037 / 1))¹ – 1. Bank B has an AER of 3.7% = (1 + (0.0365 / 4))⁴ – 1, which is equivalent to that of Bank A even though Bank B is compounded quarterly. It would thus make no difference to the investor if they placed their cash in Bank A or Bank B.

On the other hand, Bank C has the same interest rate as Bank A, but Bank C pays interest semi-annually. Consequently, Bank C has an AER of 3.73%, which is more attractive than the other two banks’ AER. The calculation is (1 + (0.037 / 2))² – 1 = 3.73%.

With a Bond

Let’s now consider a bond issued by General Electric. As of March 2019, General Electric offers a noncallable semiannual coupon with a 4% coupon rate expiring Dec. 15, 2023. The nominal, or stated rate, of the bond, is 8%—or the 4% coupon rate times two annual coupons. However, the annual equivalent rate is higher, given the fact that interest is paid twice a year. The AER of the bond is calculated as (1+ (0.04 / 2 ))² – 1 = 8.16%.

Annual Equivalent Rate vs. Stated Interest

While the stated interest rate doesn’t account for compounding, the AER does. The stated rate will generally be lower than AER if there’s more than one compounding period. AER is used to determine which banks offer better rates and which investments might be attractive.

Advantages and Disadvantages of the AER

The primary advantage of AER is that it is the real rate of interest because it accounts for the effects of compounding. In addition, it is an important tool for investors because it helps them evaluate bonds, loans, or accounts to understand their real return on investment (ROI).

Unfortunately, when investors are evaluating different investment options, the AER is usually not stated. Investors must do the work of calculating the figure themselves. It’s also important to keep in mind that AER doesn’t include any fees that might be tied to purchasing or selling the investment. Also, compounding itself has limitations, with the maximum possible rate being continuous compounding.

Special Considerations

AER is one of the various ways to calculate interest on interest, which is called compounding. Compounding refers to earning or paying interest on previous interest, which is added to the principal sum of a deposit or loan. Compounding allows investors to boost their returns because they can accrue additional profit based on the interest they’ve already earned.

One of Warren Buffett’s famous quotes is, “My wealth has come from a combination of living in America, some lucky genes, and compound interest.” Albert Einstein reportedly referred to compound interest as mankind’s greatest invention. 

When you are borrowing money (in the form of loans), you want to minimize the effects of compounding. On the other hand, all investors want to maximize compounding on their investments. Many financial institutions will quote interest rates that use compounding principles to their advantage. As a consumer, it is important to understand AER so you can determine the interest rate you are really getting.

What Is a 403(b) Plan?

The term 403(b) plan refers to a retirement account designed for certain employees of public schools and other tax-exempt organizations. Participants may include teachers, school administrators, professors, government employees, nurses, doctors, and librarians.

The 403(b) plan, which is closely related to the better-known 401(k) plan, allows participants to save money for retirement through payroll deductions while enjoying certain tax benefits. There’s also an option for the employer to match part of the employee’s contribution.

How 403(b) Plans Work

As noted above, individuals employed by schools and other tax-exempt organizations can save for retirement by contributing to a 403(b) plan through payroll deductions. The plan is akin to the 401(k) plan used by private-sector employees. Participants can include:

• Employees of public schools, state colleges, and universities
• Public school employees of Indian tribal governments
• Church employees
• Employees of tax-exempt 501(c)(3) organizations
• Ministers and clergy members

The 403(b) plan has the same caps on yearly contributions that come with 401(k) plans. The maximum contributions allowed are $20,500 and $22,500 for the 2022 and 2023 tax years respectively. For 2022, he plan also offers $6,500 catch-up contributions for those age 50 and older, increasing to $7,500 for 2023. Combined employee and employer contributions are limited to the lesser of $61,000 in 2022 and $66,000 in 2023 or 100% of the employee’s most recent yearly salary.

Participants must reach age 59½ before withdrawing funds or get slapped with an early withdrawal penalty. 

Special Considerations

Although it is not very common, your job situation could end up giving you access to both a 401(k) and a 403(b) plan. Each offers employees a tax-advantaged way to save for retirement, but investment choices are often more limited in a 403(b) plan than a 401(k). And remember, 401(k)s serve private-sector employees.

But unlike a 401(k), the 403(b) plan also offers a special plan for those with 15 or more years of service with the same employer (see below).

Types of 403(b) Plans

There are generally two broad types of 403(b) plan—the traditional and the Roth. Not all employers allow employees access to the Roth version.

A traditional 403(b) plan allows the employee to have pretax money automatically deducted from each paycheck and paid into a personal retirement account. The employee has put away some money for the future and at the same time reduced his or her gross income (and income taxes owed for the year). The taxes will be due on that money only when the employee withdraws it.

A Roth 403(b) requires that after-tax money be paid into the retirement account. There’s no immediate tax advantage. But the employee will not owe any more taxes on that money or the profit it accrues when it is withdrawn.

Advantages and Disadvantages of 403(b) Plans

There are distinct benefits and drawbacks of holding a 403(b) plan. We’ve highlighted some of the most common ones below.

Advantages

Earnings and returns on amounts in a regular 403(b) plan are tax-deferred until they are withdrawn. Earnings and returns on amounts in a Roth 403(b) are tax-deferred if the withdrawals are qualified distributions.

Certain 403(b) plans are not required to meet the onerous oversight rules of the Employee Retirement Income Security Act (ERISA). As such, these plans tend to come with lower administrative costs, which puts more money back into the employee’s pocket.

Many 403(b) plans vest funds over a shorter period than 401(k)s, and some even allow immediate vesting of funds, which 401(k)s rarely do.

If an employee has 15 or more years of service with certain nonprofits or government agencies, they may be able to make additional catch-up contributions to a 403(b) plan. Under this provision, you can contribute an additional $3,000 a year, up to a lifetime limit of $15,000. And unlike the usual retirement plan catch-up provisions, you don’t have to be 50 or older to take advantage of this as long as you worked for the same eligible employer for the whole 15 years.

Disadvantages

Funds withdrawn from a 403(b) plan before age 59½ are subject to a 10% tax penalty, although you may avoid the penalty under certain circumstances, such as separating from an employer at age 55 or older, needing to pay a qualified medical expense, or becoming disabled.

A 403(b) may offer a narrower choice of investments than other plans. Although these plans now offer mutual fund options inside variable annuity contracts. you can only choose between fixed and variable contracts, and mutual funds inside these plans⁠—other securities, such as stocks and real estate investment trusts (REITs), are prohibited.

The presence of an investment option that 403(b)s favor is, at best, a mixed blessing. When the 403(b) was invented in 1958, it was known as a tax-sheltered annuity. While times have changed, and 403(b) plans can now offer mutual funds, as noted, many still emphasize annuities.

Financial advisors often recommend against investing in annuities within a 403(b) and other tax-deferred investment plans. Accounts may lack the same level of protection from creditors as plans that require ERISA compliance. If you are at risk of creditors pursuing you, speak to a local attorney who understands the nuances of your state as the laws can be complex.

Another disadvantage of non-ERISA 403(b)s is their exemption from nondiscrimination testing. Done annually, this testing is designed to prevent management-level or highly compensated employees from receiving a disproportionate amount of benefits from a given plan.