JPYC, a Japanese yen stablecoin, briefly traded at several times its intended value after listing on South Korean exchange Upbit on Sept. 17.
Upbit market data showed the first JPYC trade went through at 12 won at 5:05 p.m. Taipei time. By 6:23 p.m., the token had climbed to 37.6 won. With 1 yen worth about 8.86 won that day, the peak price put one JPYC at roughly 4.2 yen.
JPYC is classified as an electronic payment instrument under Japan’s Payment Services Act. According to issuer JPYC, the token is backed by yen deposits and Japanese government bonds, and the official issuance and redemption window operates at a fixed rate of 1 JPYC for 1 yen.
Trading volume in the first hour on Upbit reached 79.08 billion won. The move did not last long. JPYC fell to 8.92 won at 1:32 a.m. on Sept. 18 and was quoted at 8.88 won at 5 p.m. the same day, back near 1 yen. Traders who bought at the top were facing a paper loss of about 76%.
Limited deposit access left little supply available in Korea
Japanese media outlet CoinPost, citing on-chain statistics, reported that only about 133 million JPYC existed on Ethereum before the listing. That represented 7% of the total circulating supply of 1.9 billion tokens. Upbit initially opened deposits only through Ethereum, leaving limited inventory available for buyers in the Korean market.
According to Atarashii Keizai, Upbit added Polygon and Kaia deposits at 5:44 p.m. JPYC hit its intraday high at 6:23 p.m. and then turned lower.
Arbitrage drove supply growth as traders minted in Japan and sold in Korea
The premium created an arbitrage window. Traders could mint JPYC in Japan at 1 yen and move it into Korea to sell at a much higher market price. Data from on-chain tracker JPYC Info showed circulating supply rose from about 1.896 billion on Sept. 16 to about 4.258 billion a day later, or 2.25 times the earlier level.
JPYC also temporarily paused mint reservation requests that evening. Ethereum mint reservations were halted at around 7:30 p.m., followed by Polygon at 9:19 p.m. The two networks resumed service at 10:43 p.m. and 11:22 p.m., respectively. The company said the reason was still under investigation.
Issuer representative said a stablecoin does not rise just because it lists
JPYC representative director Noritaka Okabe had flagged the unusual pricing before trading opened on Upbit. At 11:46 a.m. on Sept. 17, he quoted a social media post discussing a higher JPYC price and wrote, 「ステーブルコインは取引所に上場しても上がりませんよ」, which means, “A stablecoin does not go up just because it gets listed on an exchange.”
He added that it might be bots buying by mistake or traders targeting early liquidity.
PYUSD saw a similar move on the same day
PayPal USD (PYUSD), which also listed on Upbit earlier that day, showed a similar pattern. It rose from 1,377 won to 1,760 won, then returned to 1,383 won about half an hour later. PYUSD is pegged to $1, and its normal price was around 1,380 won.
Why JPYC surged and what the token is
The reported reason JPYC briefly traded above 4 yen on Upbit was the narrow initial deposit channel. Because Ethereum held only about 133 million JPYC, or 7% of total supply, Korean buyers could not access enough tokens at the start of trading, pushing the market price up to 37.6 won.
JPYC is an electronic payment instrument under Japan’s Payment Services Act, backed by yen deposits and Japanese government bonds. The issuer’s official window handles issuance and redemption at 1 JPYC for 1 yen, with a per-transaction cap of 1 million yen.