Home › Calculators › SK Hynix ADR Premium
SK Hynix ADR Premium Calculator
Compare the Nasdaq SK Hynix ADR with the Seoul-listed 000660.KS ordinary share after applying USD/KRW and the official 10-to-1 ADR ratio. Live inputs load when available and every field remains editable.
Fair value per ADR is (000660.KS price ÷ USD/KRW) ÷ 10. Premium is ADR price ÷ fair value − 1. For example, an ADR at $149, a Seoul share at ₩2,180,000 and USD/KRW at 1,500.16 imply fair value near $145.32 and a premium near 2.53%. The markets do not overlap, so this is a cross-close comparison, not a guaranteed arbitrage spread.
Compare the timestamps before the percentages
The US and Korean markets do not overlap. Recheck the USD/KRW leg and both quote times before treating a premium or discount as actionable.
Open the USD/KRW converter →How it works
What this calculator compares
SK Hynix trades in Seoul as 000660.KS in Korean won and in the United States through American depositary shares. The SEC prospectus states that each ADS represents one-tenth of an ordinary share. Ten ADRs therefore correspond to one Seoul share.
The formulas
Seoul share in USD = Seoul share price in KRW ÷ USD/KRW
Fair ADR in USD = Seoul share in USD ÷ ADR ratio
Premium % = (ADR market price ÷ fair ADR − 1) × 100
A positive result means the ADR is priced above the converted Seoul share. A negative result means it is priced below it. The reverse calculation, ADR price × ratio × USD/KRW, shows the Seoul price implied by the ADR.
Worked example
With 000660.KS at ₩2,180,000 and USD/KRW at 1,500.16, the Seoul share is worth about 2,180,000 ÷ 1,500.16 = $1,453.18. Divide by 10 and fair value is about $145.32 per ADR. If the ADR is $149, the comparison is 149 ÷ 145.32 − 1 = 2.53%.
Why the two prices are asynchronous
The Korea Exchange closes before the US session opens. During US hours, the calculator compares the current ADR with the latest Seoul close; that gap includes news and market moves that happened after Korea closed. After Seoul trades, the direction reverses: the Korean share is responding to the previous US close. The page labels the comparison basis from the quote timestamps.
Live data and manual fallback
The page requests a same-origin PipGauge endpoint that reads public market snapshots for SKHY or its temporary when-issued symbol SKHYV, 000660.KS and USD/KRW. These are prototype observations rather than exchange-certified trading data. Every input stays editable, and if the lookup fails the calculator continues to work with prices entered manually.
What can make the ratio misleading
- Stale legs. US and Korean holidays differ. A quote more than 30 hours old is marked stale and should not be treated as a fresh signal.
- Corporate actions. Splits or a depositary-ratio change alter the conversion. Verify the current ADR ratio before relying on the result.
- Conversion restrictions. A numerical gap does not mean an investor can freely create or cancel ADRs and lock in the difference.
- FX timing. Using a current exchange rate with an older equity close introduces another timing mismatch.
Common mistakes
- Multiplying by 10 instead of dividing. One ADR represents one-tenth of a Seoul share, so the converted share value is divided by 10.
- Flipping USD/KRW. The input is Korean won per one US dollar. Convert won to dollars by dividing.
- Calling the gap pure arbitrage. The exchanges do not overlap, liquidity differs and depositary conversion can be restricted.