Definition and Basic Structure of Mutual Funds
A mutual fund is a financial product that pools money from many investors and has a professional fund manager invest it across stocks, bonds, real estate, and other assets. As of 2024, roughly 6,000 publicly offered mutual funds exist in Japan, with total net assets reaching approximately 200 trillion yen (about 200 man-yen units, where 1 man-yen = 10,000 yen). Mutual funds have surged in popularity alongside the spread of the Tsumitate NISA (Japan's tax-advantaged savings program) as a way for individual investors to achieve diversification with small amounts of capital.
The basic structure of a mutual fund involves three parties: the investment trust management company (which makes investment decisions), the trustee bank (which holds assets in segregated custody), and the distributor (securities firms or banks that sell the fund). Because investor assets are held separately by the trustee bank, they are protected even if the management company or distributor goes bankrupt. The net asset value (NAV) is calculated once per day, and investors buy or redeem shares at this NAV.
Index Funds vs. Actively Managed Funds
Mutual funds are broadly classified into index (passive) funds and actively managed funds. Index funds aim to replicate the performance of a benchmark such as the Nikkei 225 or S&P 500, with annual management fees typically around 0.1-0.3%. Actively managed funds rely on a fund manager to select securities in an attempt to outperform the benchmark, but their management fees are higher at roughly 1.0-2.0% per year.
Data over the past 20 years shows that approximately 80% of actively managed funds have underperformed their index counterparts. If you invest 1 million yen at an annual return of 5% over 30 years, an index fund charging 0.2% grows to roughly 3.85 million yen, while an actively managed fund charging 1.5% reaches only about 2.82 million yen - a gap of roughly 1 million yen attributable solely to fees. This reality underpins the recent boom in index investing.
Common Misconceptions and Practical Considerations
The most common misconception is that mutual funds guarantee your principal. Unlike bank deposits, mutual funds fluctuate in value based on market performance, and you can lose money. During the 2008 global financial crisis, many equity mutual funds experienced NAV declines of 40-50%. Introductory books on fund selection cover these points in detail
From a practical standpoint, always check the three layers of cost: the purchase fee (sales commission), the trust fee (ongoing management expense), and the redemption fee (trust asset retention amount). No-load funds with zero purchase fees are the norm at online brokerages, but bank branches may charge 2-3%. A 3% purchase fee on a 1 million yen investment means you start 30,000 yen in the red from day one.