KOSPI Rally Swells Tax Revenue, Sparking Debate on Capital Gains Tax; Crypto Taxation to Proceed as Planned

A historic KOSPI rally has significantly boosted securities transaction tax (STT) revenue, creating a policy dilemma for the government.

Authorities are now weighing whether to reintroduce a capital gains tax on stocks, which was previously shelved, while sticking to the plan to tax crypto assets from 2027.

The current stance is to proceed with crypto taxation as scheduled and postpone the debate on a stock gains tax, prioritizing fiscal stability from the STT windfall.

The recent surge in the KOSPI has significantly increased tax revenues, sparking a fresh debate on South Korea's financial tax policies.

The story begins in late 2024, when the government decided to abolish the Financial Investment Income Tax (often called 'Geumtuse'), a type of capital gains tax on stocks, and simultaneously postponed taxing virtual asset income until 2027. This created an imbalance where stock gains remained largely untaxed (beyond the transaction tax), while crypto gains were set to be taxed.

To make up for the anticipated revenue loss from scrapping the Geumtuse, the government took a different route. First, it raised the Securities Transaction Tax (STT) rate starting from January 1, 2026. The STT is a tax levied on the seller for every stock transaction, regardless of profit or loss.

Then, an unexpected market boom happened. The KOSPI rallied ऐतिहासिकally, breaking through the 7,000-point mark for the first time in early May 2026. This led to record trading volumes. The combination of a higher STT rate and massive trading volumes created a revenue windfall for the government, so much so that it helped fund a 26.2 trillion won supplementary budget. This turned the STT from a simple tax into a crucial source of fiscal revenue.

This brings us to the current dilemma. On one hand, the government is now fiscally dependent on the high STT revenues, making it reluctant to replace it with a capital gains tax anytime soon. On the other hand, the President has publicly pointed out that the STT is regressive, as it burdens all investors equally, even those who lose money on trades. This raises questions of fairness, especially with the crypto tax still on track for 2027. For now, officials have confirmed that the crypto tax will proceed as planned, signaling that any major changes to stock taxation are off the table for the immediate future.

Securities Transaction Tax (STT): A tax charged on the total value of a stock sale, regardless of whether the investor made a profit or loss.
Financial Investment Income Tax (Geumtuse): A shelved tax plan that would have taxed profits (capital gains) from financial investments, including stocks.
Regressive Tax: A tax that takes a larger percentage of income from low-income earners than from high-income earners. In this context, it refers to the STT being applied uniformly, which can disproportionately affect small investors or those who incur losses.

KOSPI Rally Swells Tax Revenue, Sparking Debate on Capital Gains Tax; Crypto Taxation to Proceed as Planned

A historic KOSPI rally has significantly boosted securities transaction tax (STT) revenue, creating a policy dilemma for the government.

Authorities are now weighing whether to reintroduce a capital gains tax on stocks, which was previously shelved, while sticking to the plan to tax crypto assets from 2027.

The current stance is to proceed with crypto taxation as scheduled and postpone the debate on a stock gains tax, prioritizing fiscal stability from the STT windfall.

The recent surge in the KOSPI has significantly increased tax revenues, sparking a fresh debate on South Korea's financial tax policies.

Securities Transaction Tax (STT): A tax charged on the total value of a stock sale, regardless of whether the investor made a profit or loss.
Financial Investment Income Tax (Geumtuse): A shelved tax plan that would have taxed profits (capital gains) from financial investments, including stocks.
Regressive Tax: A tax that takes a larger percentage of income from low-income earners than from high-income earners. In this context, it refers to the STT being applied uniformly, which can disproportionately affect small investors or those who incur losses.