OpenAI's IPO Filing and KOSPI Buy Sidecar: The Structural Reigniting of the AI Semiconductor Rally

Amid extreme volatility in global financial markets, the KOSPI index recently executed an 8% rebound, triggering a buy sidecar. At the center of this unusual recovery following a market plunge are the leading domestic semiconductor stocks, driven by a strong influx of foreign net buying. SK Hynix surged over 15% from the previous day, while Samsung Electronics rebounded by 9%, propelling the index higher. The structural backdrop to this dramatic recovery in investor sentiment is OpenAI's confidential Initial Public Offering (IPO) filing and the reaffirmation of structural demand within the global AI semiconductor value chain.

OpenAI's Confidential IPO Filing and the $1 Trillion Valuation

One of the core catalysts reversing the market mood is the report of OpenAI's confidential IPO filing. As of June 2026, OpenAI is understood to have submitted confidential paperwork to the U.S. Securities and Exchange Commission (SEC) to go public. Having achieved a post-money valuation of approximately $852 billion during its most recent funding round in March 2026, the company is reportedly targeting a valuation exceeding $1 trillion in its public market debut.

In the capital markets, OpenAI's move to go public is interpreted as more than just an individual corporate event; it serves as a strong signal that the AI infrastructure build-out cycle has not yet reached its peak. Given the massive computational resources required for the AI ecosystem, raising large-scale capital through public markets directly translates to further data center expansion and sustained demand for high-performance AI chips.

Global AI Infrastructure Chain Reaction and Memory Semiconductors

OpenAI's strategic progression is stimulating infrastructure investment sentiment among major global tech companies. Elon Musk's plans for a massive AI chip manufacturing facility for Tesla, combined with the Nvidia CEO's positive outlook on next-generation accelerator demand, have prompted a broad revaluation of the semiconductor sector.

These global tech dynamics were immediately reflected in the Korean equity market.

• SK Hynix: Leveraging its leadership in the High Bandwidth Memory (HBM) market, the stock recorded a 15% surge as strong foreign bottom-fishing capital flowed in. This reflects the market consensus that the supply shortage for HBM3E and next-generation products is unlikely to be resolved in the short term.
• Samsung Electronics: Benefiting from the perception of being oversold and expectations of expanding market share in the next-generation AI memory market, the stock staged a robust 9% rebound.
• Micron: Leading the tech rally in the U.S. market on forecasts of increasing memory semiconductor demand, Micron provided a positive reference point for the domestic memory giants.

Divergence in Sentiment Indicators and the Buy Sidecar

It is noteworthy that this rebound occurred while major investor sentiment indicators, such as the Crypto Fear & Greed Index, were pointing to 'Extreme Fear.' Despite a general downtrend in risk assets like Bitcoin, capital is highly concentrated in AI infrastructure stocks that possess clear earnings visibility and structural demand, creating a deeply bifurcated market.

The temporary suspension of program buy orders (buy sidecar), triggered by the rapid rise in KOSPI futures prices, indicates an explosive short-term influx of algorithmic buying. This is the result of institutional investors determining that, despite macroeconomic uncertainties, the earnings estimates for companies at the top of the AI value chain remain fundamentally solid.

Conclusion and Implications

OpenAI's IPO push and the corresponding surge in domestic semiconductor large-caps demonstrate that the growth of the AI industry has entered a new phase of capital raising. Even amid macroeconomic volatility and constrained overall sentiment, the concentration of funds into core sectors with proven fundamentals is likely to persist. Market participants should focus on identifying the bottlenecks in AI infrastructure and the companies poised to benefit from large-scale capital expenditures, rather than reacting to short-term index fluctuations.