What Is an Investment Portfolio? How Individual Investors Build One to Maximize Returns While Managing Risk

In an investment market susceptible to economic conditions and social circumstances, a mechanism that maximizes returns while minimizing risk is indispensable. That is why building an investment portfolio is so important. This article explains the role and importance of a portfolio, the steps to build one, and key management points.

What Is an Investment Portfolio?

An investment portfolio is a tool for understanding the asset composition an investor holds—cash, deposits, equities, real estate, bonds, and more. It compiles specific holdings and their allocation ratios and is used as a benchmark for risk hedging.

The word "portfolio" derives from the Italian "Portafoglio" (a wallet for bills), and in English it means a document holder. In the context of finance and investment, it refers to the investment strategy itself for clarifying asset allocation and diversifying risk.

Why Is Building a Portfolio Important?

The reasons portfolios matter can be summarized in three points.

1. Asset Allocation Becomes Clear

When investing in multiple financial products in a diversified manner, it is essential to understand where and how much of your assets are allocated. Since asset allocation also fluctuates with market movements, having a portfolio lets you immediately check your current situation.

2. You Can Grasp Risk and Return

By clarifying the risk and return for each asset held, you can respond flexibly to sharp market swings. This helps prevent you from focusing too much on return while overlooking risk, or vice versa.

3. Stability Is Maintained Even Through Market Volatility

As the proverb says, "Don't put all your eggs in one basket." By distributing assets across multiple categories, losses from a sudden drop in one area are cushioned by others. Having clear risk-return-based asset allocation in place on a daily basis makes it easier to avoid major losses.

What Are the Steps to Build a Portfolio?

Portfolio building proceeds through the following four steps.

Step 1: Set Your Target Return

Set a concrete target return based on your investment goals. For "securing retirement funds," aim for 5% or more; for "steadily growing assets," aim for an average return; set figures according to your purpose. It is important to set these figures with taxes in mind.

Step 2: Set Your Risk Tolerance

Risk tolerance is determined by factors such as "investment horizon," "portfolio size," "whether you have income," and "age." Rather than percentages alone, it is important to judge individually based on your own personal circumstances.

Decide on your asset location (the ratio of cash to risk assets) and review it as life events and income changes occur.

Step 3: Set Your Investment Horizon

The longer the investment horizon, the greater the risk of sharp rises and falls, so it is necessary to think carefully about the investment period for each financial product.

Step 4: Set the Ratio of Highly Liquid Assets

Decide in advance how much of your holdings should be in highly liquid assets that can be converted to cash at any time, in preparation for unexpected expenses.

What Are the 10 Investment Methods to Include in a Portfolio?

Investment Method	Characteristics	Risk Level
Equities	Mainstream investment method earning profits from price differences and dividends	Medium–High
Investment trusts	Diversified investment possible from small amounts; managed by professionals	Low–Medium
Foreign currency deposits	Targeting exchange rate gains; generally operated with surplus funds	Medium
FX	Foreign currency trading with leverage up to 25x	High
Government bonds	Bonds issued by the government; extremely low risk of losing principal	Low
Cryptocurrency (virtual currency)	Large price movements in short periods; risk of hacking	High
ETFs (exchange-traded funds)	Track indices such as the Nikkei 225; low fees	Low–Medium
Individual corporate bonds	Principal and interest returned at maturity; credit risk of the company	Low–Medium
Gold	Universal safe-haven asset; less affected by social conditions	Low
Real estate investment	Stable operating income from rental revenue	Medium

In particular, portfolio construction incorporating real estate is attracting attention from the perspectives of inflation hedging and stable income gains.

What Are the Two Key Points for Portfolio Management?

Regularly Evaluate Performance

Not only do your holdings change over time, but the performance you seek also changes with your life stage. Evaluate performance based on your personal circumstances at the time and revise your strategy as needed.

Regularly Revise the Portfolio

To maintain target returns and risk tolerance without being swayed by market fluctuations, regularly revising the portfolio—while also utilizing expert second opinions—is essential. It is important not to miss changes in the market and broader circumstances, and to respond flexibly while also taking life stage into account.

Frequently Asked Questions (FAQ)

Q. What kind of portfolio should investment beginners start with?

A diversified portfolio centered on low-risk products such as investment trusts and ETFs, combined with government bonds and gold, is recommended. Gradually increase the ratio of risk assets as you develop investment skills.

Q. How often should I review my portfolio?

Once every six months to a year is generally appropriate, but review is also recommended when there are large market movements or life events (marriage, childbirth, career changes, etc.).

Q. What are the benefits of including real estate investment in a portfolio?

Real estate has less sudden volatility than financial products and offers stability, providing continuous income gains through rental revenue. It also has inflation-hedging effects and is effective as part of diversified investment.