India
India taxes every crypto trade: 1% is withheld at source on each sale and gains pay 30% with no loss offsets. People still buy dollars this way, so on Indian exchanges a USDT costs more rupees than the official dollar does. Over the last 200 days that premium has run between 0.4% and 9.0%, with a median of 4.2%. HWAN lists it as a weekly market, with the same contract, collateral and settlement as the Korea markets.
The settlement value
S = ( CoinDCX USDT/INR, 24-hour average ending at expiry )
/ ( ECB USD/INR reference rate of the expiry day ) - 1
- The 24-hour average uses CoinDCX's 1-minute closes, 1,440 of them. A minute without trades carries the last close forward.
- Expiry is Friday 17:00 UTC (
INDIA_EXPIRY_SECOND_OF_DAY = 61_200in the program), after the
ECB has published the day's rates. Markets open only on ECB business days, as in Korea. - The arithmetic is exact and shared with Korea:
computeIndexinengine/sdk/kimchi-index.ts, run bynode keeper/keeper.ts index-in <YYYY-MM-DD>.
Sources anyone can query
| Leg | Endpoint |
|---|---|
 CoinDCX USDT/INR | https://public.coindcx.com/market_data/candles?pair=I-USDT_INR&interval=1m |
| ECB USD/INR | https://api.frankfurter.dev/v1/<YYYY-MM-DD>?from=USD&to=INR |
Why one venue
CoinDCX carries most of India's USDT/INR trading on an order book, about $0.5 million a day. The next book, WazirX, trades about $50,000 a day. Averaging the two minute by minute would let anyone move the index through the thinner book for a fraction of the cost, so the index reads CoinDCX alone.
Band and size
- Weekly markets open with a band 10 pp wide around the current premium. Over 200 days the premium moved 2.6 pp or less in 95% of weeks and 6.5 pp at most.
- The open-interest cap is $60,000 per market. It comes from the cost of holding CoinDCX 1 pp off its fair price for a whole settlement day: about $194,000 of USDT to lift its book 1%, then everyone else's trades against it, about $0.5 million a day. The cap keeps a manipulator's possible gain under a tenth of that cost and grows with CoinDCX's volume.