CoinDCX absorbs 15.99 million USDT loss from deprecated deposit address

Indian crypto exchange CoinDCX said in an Oct. 25 blog post that it lost 15.99 million USDT, the dollar-pegged stablecoin issued by Tether. The funds left an old deposit address that was exposed in a July 2025 hack and later deprecated, and the company said it absorbed the loss. On Oct. 22, CEO Sumit Gupta had said on X that "this sounds like a false alarm."

From 'false alarm' to 'operational losses'

The outflows were first made public by an outside investigator, not the exchange. CoinDCX later said it had noticed unusual activity in its systems on Oct. 21. All times below are Korea Standard Time (KST).

1. July 19, 2025CoinDCX reported a security incident. The old operational wallet infrastructure exposed in it was deprecated.
2. Oct. 21, 2026CoinDCX noticed unusual activity in its systems, it said in its Oct. 25 blog post.
3. Oct. 22, 12:35 a.m.According to Darcy, co-founder of fund-tracing firm FlashRescue, about 15.99 million USDT and 5,783.81 TRX moved from CoinDCX wallets to a single Tron address at this time.
4. Oct. 22, 2:30 p.m.Darcy flagged the transfers on X. The largest single transfer was 15,819,002 USDT, and the funds were split several times and sent to deposit addresses at Binance, OKX and Gate, Darcy wrote.
5. Oct. 22, 5:10 p.m.Gupta replied that "CoinDCX wallets are not breached," saying the hackers appeared to be reusing old addresses. Four minutes later, the company account said "Users' funds are safe" and called the claims "misleading."
6. Oct. 22, 8:47 p.m.The company said the process that sweeps deposits from old addresses had failed for a period, which "led to some operational losses." It gave no figure.
7. Oct. 25The blog post disclosed the loss as 15.99 million USDT for the first time.

Credited at once, swept later

According to CoinDCX, some users kept sending funds to the deprecated address. The exchange displayed new addresses in its app and told users not to use the old ones, but handled mistaken deposits in two steps rather than leave them stranded. Funds arriving at an old address were credited to the user's account immediately, and a separate "sweeping" service then moved them into the company's primary wallet.

This time the sweeping service failed for a particular period, and deposits accumulated at the old address. The company said the old wallet infrastructure had "unknown vulnerabilities." Because user balances had already been credited, customer deposit balances were unaffected, and customer assets are held in segregated cold wallets (storage kept offline), the company said. It added that there had been no trading halt or withdrawal limits over the previous 72 hours.

CoinDCX said "We could have been more proactive," but that it shared the update as soon as it had the complete picture. It said it would strengthen monitoring of residual systems and regularly remind users that support for deprecated addresses is time-bound.

ZachXBT says the address stayed in use for 10 more months

Onchain investigator ZachXBT offered a different account. He wrote that the deposit address in question was used by a liquidity provider (LP) for 10 months after last year's incident, and that user deposits at that address were swept to the company's current public hot wallet as recently as April and May this year. That meant $15.8 million in user deposits was unaccounted for by the company, he argued.

Replying to ZachXBT, Gupta said "Yes, aware of that" and that the team was investigating further, adding that "no user funds will be at loss." Later that night, ZachXBT urged users to withdraw their funds from CoinDCX, adding that he had helped freeze six figures (hundreds of thousands of dollars) for the exchange. According to U.S. outlet The Block, CoinDCX's PR agency pointed to the blog post when asked about Gupta's earlier statements. The Block put the July 2025 loss at about $44 million.

About 21.4 billion won at Korean prices

As of around 10:30 a.m. KST on Oct. 26, USDT traded at 1,338 won on Upbit's Korean won market and 1,337 won on Bithumb. At the Upbit price, the 15.99 million USDT loss is worth about 21.4 billion won. The 5,783.81 TRX that also left the wallets was worth about 2.55 million won at Upbit's price of 441 won at the same time.

CoinDCX has no direct link to Korean won exchanges. CoinDCX advised users to check the latest deposit address in its app or website before every deposit.