CPI & Inflation: How Rising Prices Affect Your Investments

Concepts

What Is CPI and How Does It Relate to Inflation?

CPI stands for Consumer Price Index. It tracks changes in the prices of everyday goods and services purchased by households — things like food, rent, transportation, and healthcare.

When CPI rises, it means prices are going up — that is inflation. Moderate inflation (around 2%) is actually healthy and signals economic growth. But when inflation spirals out of control, central banks must step in and raise interest rates to cool things down, which typically hurts the stock market.

CPI, Core CPI, and PCE — What Is the Difference?

All three measure prices, but each has a different focus:

• CPI (Headline CPI): Includes all goods and services — the one most people hear about. The U.S. FRED code is CPIAUCSL.
• Core CPI: Strips out volatile food and energy prices to reveal the underlying price "trend." The U.S. FRED code is CPILFESL.
• PCE (Personal Consumption Expenditures Price Index): This is the Fed's preferred inflation gauge. PCE covers a broader range than CPI and automatically adjusts for consumer substitution behavior (e.g., when beef becomes expensive, consumers switch to pork). The U.S. FRED codes are PCEPI (headline) and PCEPILFE (core).

In Taiwan, the "Consumer Price Basic Classification Index" published by the DGBAS (Directorate-General of Budget, Accounting and Statistics) serves as the local equivalent of CPI. Taiwan's core CPI similarly excludes fruits, vegetables, and energy.

How Does Inflation Affect Interest Rates and the Stock Market?

This causal chain is important to remember:

1. Rising inflation → Central bank raises rates to cool the economy → Borrowing costs increase for businesses → Profits get squeezed → Stocks come under pressure
2. Falling inflation → Central bank may cut rates → Money becomes cheaper → Favorable for stock market gains

Pay special attention: the market does not just look at how high inflation is, but at which direction it is heading. If inflation is already high but starting to decline, markets may celebrate in advance. Conversely, if inflation is still accelerating, markets will get nervous even if the absolute number is not extreme.

Additionally, inflation affects different types of stocks differently. Energy and commodities — "real assets" — may actually benefit during inflationary periods. Meanwhile, high-growth tech stocks suffer the most because their future cash flows get discounted at higher rates.

Hands-On: Using CTSstock

On the CTSstock homepage (/home), the economic indicators dashboard provides:

• Taiwan CPI Year-over-Year Growth: Observe Taiwan's price trends and whether inflationary pressure is heating up or cooling down.
• U.S. CPI / Core CPI / PCE: These are the most closely watched inflation indicators globally — each release can trigger sharp market moves.

It is best to review these alongside Fed interest rate policy to assess the likely timeline for rate hikes or cuts.

FAQ

Q: Why does the Fed focus on PCE rather than CPI? A: Because PCE better reflects actual consumer behavior and covers a wider range (including employer-paid health insurance premiums, for example). The Fed's 2% inflation target refers specifically to core PCE.

Q: How often is CPI released? A: Both Taiwan and the U.S. publish CPI data monthly. In the U.S., CPI is typically released in the middle of the month for the prior month's data, making it one of the most important economic releases of the month. Stock and bond markets pay close attention each time.

Q: How does inflation affect long-term dividend investors? A: Inflation erodes your purchasing power. If your stock pays a 4% annual dividend but inflation is running at 3%, your real return is only 1%. That is why companies with "pricing power" — strong brands or providers of essential goods that can pass higher costs on to consumers — tend to hold up better during inflationary periods.