The Bitgrin (XBG) network appears to have minted billions of tokens, despite a declared max supply limit of 21 million XBG.

On June 4, leading cryptocurrency information website CoinMarketCap warned its followers about the anomaly on Twitter. The announcement reads:

“Alert Issued: We have received reports that billions of XBG were minted despite having a max supply of 21M.”

The alert is now also featured on CoinMarketCap’s dedicated BitGrin page. Interestingly, the page also notes that the coin was “launched on 31 Jan 2019 by an anonymous team of developers”. As of press time, market data showed that it appreciated by about 11.5% over the past 24 hours.

Yesterday's price change reported on the website is a gain of nearly 40.6%. Shortly after this article was published, the cryptocurrency lost 45% compared to yesterday’s price.

Alert on Bitgrin’s CoinMarketCap page. Source: CoinMarketCap

Five billion XBG mined in a single block

Bitgrin's lead developer Pharazen told Cointelegraph that exactly five billion XBG were issued as a reward for a single block on the blockchain, causing the total supply of the cryptocurrency to reach 5,021,000,000 XBG. He said that he knows that the anomaly was the manifestation of a bug because he himself mined the block in question. 

Pharazen said that he already rendered the coins inaccessible by transferring them to an address that he himself cannot access, but admitted that this cannot be proved. While he claimed that mimblewimble-enabled cryptocurrencies cannot be burned, he promised that he plans to implement a hard fork on the network to render the coins inaccessible in a publicly verifiable way.

As Cointelegraph reported at the end of 2018, a similar instance happened with Bitcoin’s fork Bitcoin Private (BTCP). The developers of the blockchain in question confirmed the creation of 2.04 million units of BTCP “that were never intended to exist on the blockchain.”