17.3 How to Accumulate Personal Wealth

Financial Markets and Investment

Stock Price Movements

Stock prices are set by the collective buying and selling decisions of investors. These decisions reflect company performance, broader economic conditions, and investor sentiment.

In the short term, stock price movements are largely unpredictable. Random walk theory describes this pattern: day-to-day price changes are independent of each other, meaning yesterday's movement tells you nothing useful about tomorrow's. You can't reliably predict where a stock will be next week.

Over the long term, though, stock prices tend to follow a general upward trend. Economic growth, inflation, and rising corporate profits all push prices higher over years and decades. This combination is sometimes called a random walk with a trend: daily movements are unpredictable, but over extended periods, investors can expect stock prices to rise (with plenty of fluctuations along the way).

Compound Interest Calculation

Compound interest is interest calculated on both the initial principal and the accumulated interest from previous periods. In other words, you earn interest on your interest, not just on what you originally invested.

The formula for the future value (FV) of an investment with compound interest:

$FV = P(1 + r)^n$

• $P$ = initial principal (the amount you invest)
• $r$ = annual interest rate as a decimal
• $n$ = number of compounding periods (usually years)

Example: You invest $1,000 at a 5% annual interest rate for 10 years.

$FV = 1{,}000(1 + 0.05)^{10} = 1{,}628.89$

Your $1,000 grew by more than $628 without you adding a single dollar. That's because each year's interest gets reinvested and earns additional interest in the following years. This is why compound interest causes investments to grow exponentially over time, and why starting early matters so much.

Role of Financial Markets

Capital Flow Facilitation

Financial markets (stock markets, bond markets) serve as platforms where savings get channeled toward productive uses. People and institutions with excess capital (savers) invest through these markets, while businesses and governments that need funding (borrowers) raise it by issuing securities. This process directs resources toward the most productive and profitable ventures.

Financial markets operate through two main channels:

• Primary market: Where new securities (stocks, bonds) are issued and sold to investors for the first time. This is how companies raise capital for expansion, research and development, or other projects.
• Secondary market: Where previously issued securities are traded among investors. This provides liquidity, meaning investors can buy or sell securities relatively easily based on their financial needs or changing expectations.

The interaction of buyers and sellers in these markets also enables price discovery, the process by which the market determines the fair value of a security. Accurate prices help investors make informed decisions and support efficient allocation of resources across the economy.

Together, these functions contribute to economic growth, job creation, and overall financial stability by keeping capital flowing to where it can be used most effectively.