XL dev

Consumer Price Index (CPI): Inflation, Interest Rates, Growth

Learn how economic growth, inflation and interest rates link to the consumer price index and how the CPI, sometimes called the inflation index, affects the stock market as well as depicts the price of goods and services.

https://tickertapecdn.tdameritrade.com/assets/images/pages/md/Balloons and pumps: Inflation and CPI; Consumer Price Index and Your Investments
3 min read
Photo by Getty Images

Whether you’re invested in bonds or considering a car loan, you should know what’s up with the Consumer Price Index (CPI). The government puts this data together to help keep track of the price of goods and services purchased by consumers in the U.S.

The CPI (which some call the "inflation index") is considered a good indicator of how well the overall economy is doing because economic growth and inflation tend to go hand in hand. But if inflation gets too high, a central bank such as the U.S. Federal Reserve might raise interest rates to try to keep the economy from overheating. That can have an impact on the value of bonds in your portfolio, as well as the interest rate on any loans you might want to take out.

“As an investor, you want to keep track of the inflation rate,” said Shawn Cruz, senior market structure specialist with TD Ameritrade’s active trader group.

Historically, when you start to see the economy pick up and unemployment drop, you may expect to see CPI inflation rise. Essentially, when buyers of certain goods and services are more aggressive than sellers, prices can trend higher. That’s price inflation in a nutshell.

Some members of the Federal Reserve Board use personal consumption expenditures (PCE) index data as an inflation benchmark, but the CPI gets more press in part because it is so widely used within the government. “It’s the benchmark for Social Security payments,” Cruz said. “The two data sets differ in how they are calculated and what’s included in their baskets of goods and services.”

Also, there are a few financial contracts—such as Treasury Inflation-Protected Securities—that are tied to inflation data, he noted.

So What’s Going On with CPI?

In the 12 months through December 2017, the CPI has gained 1.8%, according to the Bureau of Labor Statistics.

That’s shy of the central bank’s target of 2%. (Although the Fed’s target is related to the PCE, both the PCE and CPI tend to track closely together, Cruz noted.)

It can be troubling when inflation undershoots the Fed target, Cruz said, because it brings up worries about deflation. The dreaded d-word happens when inflation rates are negative, or, more simply put, when prices fall. That’s not something to celebrate, because a deflationary period can be marked by falling gross domestic product.

“Deflation can really wreak havoc on an economy,” Cruz said.

This could leave the Fed in a bit of a bind.

On the one hand, some say the Fed should raise interest rates more because we are far into an expansionary economy, and the central bank needs to have more room to loosen monetary policy the next time the economy starts to slow down.

On the other hand, some say if the Fed tightens too much or too soon, that could send the economy into recession—the very thing it's trying to prevent.

The Fed raised rates three times in 2017, each time by 25 basis points. After its December 2017 meeting, the central bank said it was planning three more such hikes in 2018.

Low Inflation and the Markets

If inflation stays low, however, that might lower the likelihood that the Fed would raise rates, Cruz says.

That could bode well for bonds. Because bond prices fall as interest rates rise, accommodative Fed policy would put less downward pressure on their prices.

Some argue that the low interest rate environment has been a boon to asset prices, including stocks, over the last several years. But when prices aren’t rising, some companies, such as retailers, auto dealers, or any company that sells goods or services, might have a harder time growing their top-line revenues.


Related Videos

Call Us

Content intended for educational/informational purposes only. Not investment advice, or a recommendation of any security, strategy, or account type.

Be sure to understand all risks involved with each strategy, including commission costs, before attempting to place any trade. Clients must consider all relevant risk factors, including their own personal financial situations, before trading.

Investments in fixed income products are subject to liquidity (or market) risk, interest rate risk (bonds ordinarily decline in price when interest rates rise and rise in price when interest rates fall), financial (or credit) risk, inflation (or purchasing power) risk and special tax liabilities. May be worth less than the original cost upon redemption.


Market volatility, volume, and system availability may delay account access and trade executions.

Past performance of a security or strategy does not guarantee future results or success.

Options are not suitable for all investors as the special risks inherent to options trading may expose investors to potentially rapid and substantial losses. Options trading subject to TD Ameritrade review and approval. Please read Characteristics and Risks of Standardized Options before investing in options.

Supporting documentation for any claims, comparisons, statistics, or other technical data will be supplied upon request.

This is not an offer or solicitation in any jurisdiction where we are not authorized to do business or where such offer or solicitation would be contrary to the local laws and regulations of that jurisdiction, including, but not limited to persons residing in Australia, Canada, Hong Kong, Japan, Saudi Arabia, Singapore, UK, and the countries of the European Union.

TD Ameritrade, Inc., member FINRA/SIPC, and a subsidiary of TD Ameritrade Holding Corporation. TD Ameritrade Holding Corporation is a wholly owned subsidiary of the Charles Schwab Corporation. TD Ameritrade is a trademark jointly owned by TD Ameritrade IP Company, Inc. and The Toronto-Dominion Bank. © 2020 Charles Schwab & Co., Inc. Member SIPC.

Scroll to Top