[In-Depth Analysis] Reignited Debate on 2027 Financial Investment Income Tax: 3 Key Reasons for Retail Investor Backlash

Introduction

As the full implementation of the Financial Investment Income Tax nears its scheduled date next year, tension is mounting within the capital markets. While tax authorities emphasize the fundamental principle of taxation—that taxes should follow income—retail investor groups are strongly demanding its complete abolition, citing the structural vulnerabilities of the domestic stock market. With policy uncertainty amplifying market volatility, we analyze the three main arguments behind the retail investors' backlash.

1. Tax Equity and the Burden of Double Taxation

The most immediate reason for retail investors' opposition is the issue of tax equity. Currently, participants in the domestic equity market pay a securities transaction tax of around 0.2% upon selling shares. Investors point out that introducing a capital gains-like financial investment tax without fully eliminating the existing transaction tax creates a de facto double taxation structure.

Furthermore, changes to the taxation system for indirect investment products, such as mutual funds, have also come under scrutiny. Concerns are rising that as some previously tax-exempt products become subject to taxation, opportunities for wealth accumulation through long-term investments may be significantly reduced.

2. Capital Flight and Worsening Liquidity

The potential contraction of market liquidity is another core issue. Although the tax is estimated to apply to only about 1% of total investors, the sheer volume of capital held by these individuals exerts a massive influence on overall market liquidity.

To avoid the tax burden, there is a high probability that whale investors will aggressively sell off domestic equities before the tax takes effect, reallocating their capital to overseas markets—such as the United States—which offer clearer incentives for long-term investing or maintain a strong currency trend. With overseas stock holdings already reaching record highs in the first half of 2026, the implementation of this tax could act as a catalyst, accelerating the capital flight.

3. Worsening of the Korea Discount

Lastly, there is deep concern that the chronic undervaluation of the Korean stock market, known as the Korea Discount, will worsen. In a domestic market environment where shareholder return rates are already lower than those in developed nations, reducing tax benefits will inevitably diminish investment incentives.

Major advanced financial markets like the U.S. implement tax support measures, such as lower tax rates for long-term investors, to promote market stability. In contrast, the proposed financial investment tax structure has been criticized for lacking sufficient incentives for long-term investing, potentially encouraging short-term speculative trading. Ultimately, this carries macroeconomic risks that could weaken domestic companies' ability to raise capital and reduce the overall competitiveness of the national economy.

Conclusion: The Need for Policy Clarity and Restoring Market Trust

While realizing tax justice is important, forcing the implementation of a system without considering the foundational health of the capital market and investor protection can trigger unintended side effects. As the implementation date approaches, equity market volatility is expected to widen. It is time for policymakers to present a refined, market-acceptable alternative that balances the establishment of tax principles with the vitalization of the capital market.