Chinese Exchange LuBian’s 2020 Hack Resurfaces — $14.5B in Bitcoin Gone.
LuBian rose quickly in early 2020, becoming the sixth-largest mining pool on the Bitcoin network by mid-year.
A devastating cyberattack on Chinese Bitcoin mining pool LuBian in December 2020 has only now come to light, revealing the theft of nearly 127,426 BTC, worth around $3.5 billion at the time and an estimated $14.5 billion today.
The incident, now confirmed as the largest Bitcoin theft on record, remained undisclosed for more than four years, raising fresh concerns about transparency and custodial security in the cryptocurrency industry.
The company rose quickly in early 2020, becoming the sixth-largest mining pool on the Bitcoin network by mid-year. Its website promoted it as “the safest high-yielding mining pool in the world.”
However, by February 2021, LuBian disappeared without explanation, fueling speculation that either the authorities shut it down or it quietly converted into a private pool.
The Attack Timeline And Its Pull-Off.
According to new blockchain research by Arkham Intelligence, the breach unfolded over just a few days on December 28, 2020, hackers drained the majority of LuBian’s BTC reserves, taking roughly 90% of the pool’s funds in a single, coordinated transaction.
Furthermore, on December 29, 2020, a related wallet on Bitcoin’s Omni layer lost around $6 million in Bitcoin and Tether (USDT), then on December 31, 2020, the company moved remaining assets into recovery addresses in a desperate attempt to contain the damage.
Despite the size of the theft, the project did not issue a public disclosure or industry alert.
Arkham’s analysis suggests the attackers exploited a vulnerability in their private-key generation process rather than traditional exchange hacking techniques. This flaw allowed the perpetrators to gain complete control over the platform’s wallets without triggering immediate alarms.
In the aftermath, LuBian sent 1,516 OP_RETURN messages, a feature allowing small pieces of data to be written to Bitcoin transactions directly onto the blockchain in an attempt to contact the hacker. These messages offered a bounty for the safe return of the stolen funds.
Where is the Bitcoin Today?
While the company managed to retain around 11,886 BTC (currently worth about $1.35 billion), the hacker’s massive haul has remained largely untouched. In July 2024, the hacker consolidated the stolen coins into a single wallet address, where they still sit dormant as of mid-2025.
The inactivity has led some analysts to speculate that the attacker is either waiting for a strategic moment to move the funds or is unable to do so without exposing their identity.
Why No One Knew About the Attack on LuBian Until 2025.
The absence of public reporting in 2020 allowed the hack to slip under the radar until Arkham’s forensics team pieced together the details from historical blockchain data. The long delay in disclosure has intensified debate over whether large mining pools, exchanges, and custodians should be legally required to report significant breaches promptly.
