Shares of SK Hynix, a leading South Korean memory-chip manufacturer, recently exhibited a significant pricing disparity between its U.S.-listed American depositary receipts (ADRs) and shares traded on the Seoul stock exchange. The company raised approximately $26.5 billion through the sale of these ADRs last week, which U.S. investors can purchase using U.S. dollars and which confer the same earnings claims as the Korea-listed shares. However, unlike some depositary programs, these ADRs cannot yet be converted back into the Korean shares.

This lack of convertibility contributed to a surge in demand for the U.S. version, pushing their price to nearly a 50% premium over the shares traded domestically in South Korea. This gap runs counter to the "Law of One Price," which holds that equivalent assets should trade at roughly the same price across different markets.

Such violations of pricing parity often emerge when it becomes difficult for professional traders to engage in arbitrage—profiting from price discrepancies—while speculative activity by less experienced investors intensifies market imbalances. Similar episodes have occurred in other contexts, including during past market bubbles. For instance, in early 2000, just before the technology bubble burst, partial sales of Palm shares under parent company 3Com revealed a large pricing disconnect: the publicly traded Palm shares were significantly undervalued compared to 3Com’s remaining stake, a gap that arbitrageurs could not close effectively due to difficulties in short selling Palm shares.

Closed-end investment funds, which trade independently of their net asset values (NAVs), can also experience pronounced distortions. After the Berlin Wall fell in 1989, Germany Fund shares swung from a typical discount to a premium of nearly 100% amid heightened investor enthusiasm. More recently, the Destiny Tech100 fund, which held private shares of SpaceX, traded at prices well above the value of its holdings before SpaceX’s June initial public offering, only to decline by 60% following the market adjustment.

The Grayscale Bitcoin Trust offers another example, as it once traded at a premium of over 100% relative to the underlying bitcoin due to difficulty in direct cryptocurrency purchases. This premium reversed sharply as bitcoin access improved, with the trust experiencing a discount of up to 45% in 2023. Investors who anticipated its successful conversion to an exchange-traded fund (ETF) saw substantial gains.

While market participants may find justifications for elevated valuations of assets like SK Hynix, SpaceX, or bitcoin, the existence of divergent prices for equivalent holdings underscores risks inherent in speculative markets. Market professionals—often viewed skeptically by individual investors—play a role in aligning prices and identifying imbalances. However, relying solely on mispriced assets without accounting for such distortions can result in significant losses.

Observers suggest treating pronounced pricing discrepancies as warnings of excessive excitement rather than guaranteed opportunities, emphasizing caution in the face of market euphoria.