[Disclosure] Celltrion (068270) Announces Scheduled Derivatives Market Adjustments Following Corporate Bonus Issue

Fact Source: Financial Supervisory Service DART / 2026-05-27

Disclosure Type: Guide on Investment Precautions for Stock Futures and Options

💡 3-Second Summary

Following Celltrion’s bonus issue decision, the Korea Exchange has announced scheduled technical adjustments to reference prices, contract multipliers, and strike prices for all active stock futures and options, effective June 4, 2026.

📊 1. [Summary of Key Disclosure Content and Figures]

• Trigger for Scheduled Measures: Board of Directors’ resolution on Celltrion’s bonus issue on May 21, 2026
• Effective Implementation Date: June 4, 2026 (Ex-rights date of underlying shares)
• Target Underlying Asset: Celltrion Common Stock
• Details of Scheduled Adjustments and Formulas:
  • Reference Price Adjustments (All contract months for futures and options):
    • Adjusted Reference Price = Pre-adjusted Reference Price × (Adjusted Reference Price of Underlying Share ÷ Closing Price of Underlying Share on the Day Prior to Ex-rights Date)
  • Contract Multiplier Adjustments:
    • Target: Futures contracts with open interest as of the close of June 2, 2026, and all option contract months
    • Adjusted Multiplier = Pre-adjusted Multiplier × (Closing Price of Underlying Share on the Day Prior to Ex-rights Date ÷ Adjusted Reference Price of Underlying Share)
  • Option Strike Price Adjustments:
    • Adjusted Strike Price = Pre-adjusted Strike Price × (Adjusted Reference Price of Underlying Share ÷ Closing Price of Underlying Share on the Day Prior to Ex-rights Date)
  • Delisting of Futures Spread Contracts: Calendar spreads linking contracts with different adjusted multipliers will be officially delisted.
  • Special Listing of Options Contracts: To distinguish from fractional contract parameters, new options series with a standard contract multiplier of 10 will be newly established.
• Timeline: The final, exact numerical values for these adjustments will be computed and announced on June 2, 2026, the business day prior to the ex-rights date.

📈 2. [Professional Insight: What This Disclosure Means for Investors]

• Derivatives Neutralization Against Corporate Action: Because the spot share price of Celltrion will face an ex-rights downward adjustment on June 4, a corresponding re-balancing of related derivative contracts is required. By lowering the options strike boundaries and futures reference baselines while raising the contract multipliers, the exchange seeks to systematically insulate the net equity value of outstanding derivatives holdings against arbitrary fluctuations.
• Preemptive Disruption in Calendar Spread Operations: Due to the varying multipliers across different contract cycles, several futures calendar spreads will be delisted. This administrative removal may disrupt systematic roll-over programs commonly utilized by global macro funds, meaning that traders might need to manually exit and re-establish separate near-month and far-month legs to preserve their directional exposure.
• Risk of Operational Execution Errors: Once implemented on June 4, adjusted contracts with complex fractional multipliers will co-exist alongside newly listed series holding the standard multiplier of 10. Global institutions must ensure their quantitative trading algorithms and direct-market-access (DMA) engines are fully calibrated to parse these overlapping parameters to avoid miscalculating order margins or contract sizes.

📝 Editor’s Comment (by K-STOCK Editor)

This warning release serves as an essential regulatory roadmap outlining how Celltrion’s upcoming bonus issue will alter the mechanics of the KRX derivatives market. While the physical adjustment will only take effect on the ex-rights opening bell of June 4, the exchange is publishing the underlying mathematical formulas ahead of time to allow risk management systems to adjust. The primary risk factor to monitor is the planned delisting of specific calendar-spread instruments on the transition date. For asset allocators managing large derivatives overlay positions on Korean equities, preparing for manual roll-overs is highly advised. Traders should keep an eye out for the final numerical values, which will be calculated and finalized after the market closes on June 2.

📢 Disclaimer & Source Information

Source: This content has been structured and newly written based on official disclosure data submitted to the Financial Supervisory Service’s Electronic Disclosure System (DART).

Investment Risk Advisory: This information is provided solely for informational and linguistic reference purposes. Under no circumstances does it constitute financial advice, solicitation, or a recommendation to buy or sell any specific stock. All investment decisions and financial liabilities rest entirely with the individual investor.

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