How Interest Rates Affect Your Investments

Last Updated: October 30, 2018
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The Fed has increased them twice this year and probably it's not final. How does it impact on our investments and what can we do to deal with it?


Have you wondered what exactly is an interest rate?

An interest rate is the amount of money you have to pay if you borrow it from someone (a bank, a credit union, the local pawnbroker).

If you deposit your cash with an institution or a person, they have to pay you an interest because they use your money.  Almost everyone, if not everyone, in the US owes or is owed something.

Who is responsible for setting interests rate?

Each country has a central bank that regulates the sector and determines the level of interest rates.

How Interest Rates Affect Your Investments

The Impacts Of Interest Rates Changes

In the US, this is the Federal Reserve, in the eurozone – the European Central Bank, in the UK – Bank of England. Changing the value of interest rates is part of the monetary tools a central bank can use when trying to regulate the supply and demand.

So, rates are just one of the instrument that can affect the economy of a country.

Let’s see how interest rates affect different markets and segments of the economy:


There is a strong bond between interest rates and inflation. There is a simple and general rule: when rates go down, inflation goes up. If a central bank decides to increase rates, then inflation is expected to go down.


When rates are low, people tend to take out loans (Mortgage, auto loan or FHA loan) and generally – borrow more. This, on the other hand, makes them spend more, which leads to higher prices. Usually, economies grow in such conditions.

In contrast, increasing interest rates lead to a lower consumer spending. More people put money in bank deposits because of the higher rates. Consequently, inflation decreases due to a slack demand.

It’s simple.


The relationship between bonds and interest rates is really complicated.

Let’s look at it in detail:

The basic rule is that when interest rates rise, bond prices decrease. In financial terms, this is the so-called inverse correlation. This is also known as interest rate risk. Here, we need to consider one thing to explain this puzzle – a bond’s yield and maturity. This is the profit an investor can make for a specific period of time (let’s say 10 years).

For example:

A treasury bond offers a 2% coupon rate and market interest rates stand at 2%. Next year, however, rates drop to 1% and newly issued bonds have 1% coupon rate. The old ones, which you own, will still carry the 2% rate. That’s why, if you sell these 2% bonds you’ll get a higher price for them (because they give a higher coupon rate than the new ones.)

However, for the people who purchase these bonds, the yield to maturity will be lower than a year ago. This is why bond prices usually rise when interest rates are reduced.


Stock markets are seriously affected by changes in interest rates, and the correlation is not as obvious as with bond markets. It’s more indirect.

Just like bonds, when rates are higher, stock markets tend to slow down.

If the Fed, for instance, increases interest rates, it means that banks will borrow money from it at a higher price. Consequently, banks increase rates on their loans and lend money at a higher price.

Usually, people and businesses alike refrain from borrowing when the costs are higher. In these conditions, companies cannot normally expand and grow, sometimes they even shrink and cut back on expenditure. The price of their shares, of course, declines as a consequence.

But there’s one small catch:

In theory, this is how it goes. But in the US, following three interest rate hikes in a row, stock markets are on the rise and there are no signs of a bearish market.


Well, for now – markets take the Fed’s decisions as an indicator that the economy is strong. But let’s wait…things can change quickly.

Real Estate Market

Regarding the housing market, things could be quite confusing.

So what’s the answer

Usually, when interest rates increase, borrowing declines. Since most people purchase their homes via a mortgage, we can assume that the higher interest rate results in larger monthly installments. That, on the other hand, might dissuade people from buying property. Of course, this will affect negatively the whole sector (check your mortgage payoff changes in case of interest rate increase )

Given the current situation in the US, the Fed does not hike interest rates randomly. This is a sign of a stable and sound economy and the housing market in particular. There are many other factors which affect the industry, such as unemployment rate and political environment.

National Currencies

How do interest rates change the value of a currency?

There is a strong correlation between exchange rates and interest rates. This is one of the tools all central banks use to manipulate the price of their currencies. The rule is: the higher the rate, the stronger the currency’s value.

Remember back in 2015 how ECB President Mario Draghi was trying to stimulate the economy of the eurozone? He tried to do it by decreasing the value of the euro.

How could he do that

Besides the so-called quantitative easing, the ECB also reduced the interest rates to zero. This led to a decrease in the value of the area’s currency. This, on the other hand, had to result in more investments and money spending.

Beware that currencies are affected by many other factors.


All in all, interest rates are one of the instruments central banks use to spur the economy of a country. They affect all segments and sectors. Keep in mind that often things, in theory, are not the same as in practice. You have to consider many other factors besides interest rates and show a deeper knowledge of markets.

Regarding interest rates, the Fed has increased them twice this year. The US monetary policymaker intends to do it once later this year.

So, draw your conclusions 🙂