What Is the Kimchi Premium? Korea's Own Price Gap

The first time you learn that the same Bitcoin costs a different price on Upbit than on Binance, you tilt your head. When a Korean exchange's price sits above overseas exchanges, that gap has a name: the Kimchi Premium (kimp for short). If Korea is trading 5% pricier than abroad, that's "5% kimp." When Korea goes cheaper instead, it's a reverse premium (yeokp).

Why it doesn't vanish, the wall that blocks arbitrage

By the law of one price, a gap like this should close instantly. Buy cheap abroad, sell dear in Korea, done. But in reality a wall blocks that loop.

• Capital controls: Under Korea's foreign exchange law, individuals face limits and reporting duties on overseas remittances. Big won transfers aimed at capturing kimp get blocked at the bank, or turn into a legal problem.
• Friction between exchanges: Moving coins into Korea to sell is doable. But sending the resulting won back overseas to repeat the loop is blocked. So the arbitrage is one-and-done.
• Travel Rule and KYC: Fund-tracking rules add constraints and delays to the transfers between exchanges themselves.
• The won market's isolation: The won isn't used in international settlement. So global market makers can't instantly absorb price gaps in the won market.

In short, the kimp is a pressure gauge. It's built by liquidity trapped inside Korea and the intensity of Korean investor demand.

The extremes history has shown

The history of the kimp is the history of Korean market overheating. During the late-2017-to-early-2018 mania, the kimp shot past an unheard-of 50%. Not long after, the market slid into a long bear phase. April 2021 rhymed: a crash came right after the kimp widened to around 20%. At frozen bear-market bottoms, though, the kimp often sank near 0% or went negative (reverse premium).

Because of this pattern, people read the kimp like a Korea-only Fear & Greed Index. High kimp means Korean retail buying is overheated. A reverse premium means the Korean market has gone completely cold. Global money moves the global price, of course. So the kimp is less a directional signal for the world market and more "Korea's own thermometer."

Things to watch when reading the kimp

First, the exchange rate is half the equation. Calculating kimp runs through the won/dollar rate. So if that rate swings hard, the kimp number can lurch even when coin demand hasn't changed. Second, it differs by coin. If Bitcoin's kimp is low but one altcoin's kimp spikes, that may reflect a domestic supply-demand event for that coin (a listing, a hot theme, whatever). Third, actually trying kimp arbitrage carries serious legal and practical risk for individuals, thanks to the regulatory wall above. Reading it as an indicator and diving in yourself are totally different things.

Where and how to check it

You can work out the kimp yourself: (domestic won price ÷ (overseas dollar price × won/dollar rate) − 1) × 100. For example: 140 million won on Upbit, 100,000 dollars on Binance, a rate of 1,350 won. That's about 3.7% kimp. You don't have to crunch it every time, obviously. Several Korean services aggregate the kimp in real time, so a quick search pulls it up. While you're there, compare the Bitcoin kimp against the altcoin kimp. It helps you tell whether domestic demand is a market-wide fever or one coin's event.

Wrapping up

The Kimchi Premium is a graph drawn by Korean investor psychology on top of a structural wall of capital controls. An extremely wide kimp has often read as overheating, and a deep reverse premium as cooling. But that's a probabilistic tendency, not a law. For the record, the octopus on this site doesn't factor the kimp into its math. The five indicators it actually reads are in the full algorithm reveal.