Jim Cramer says he plans to sell his entire bitcoin holding because he believes advances in quantum computing could break the cryptocurrency’s security within about three years.
The CNBC Mad Money host made the comments after a 30 July interview with IBM Chairman and CEO Arvind Krishna, who warned investors to be “paranoid” about quantum computing’s ability to challenge modern cryptography within three to four years.
Krishna’s assessment, based on IBM’s progress towards commercially useful quantum machines, immediately renewed debate among bitcoin investors about whether the threat is moving from theory towards a practical engineering problem.
Cramer said he intended to leave his bitcoin position altogether, arguing that a sufficiently advanced quantum computer could threaten the Bitcoin network on a similar timescale.
His comments spread rapidly across social media, where the reaction quickly became as prominent as the warning itself. Traders have long treated Cramer’s market predictions as potential contrarian indicators, a habit that has contributed to the popularity of the so-called “inverse Cramer” trade.
Within minutes, crypto users were posting messages celebrating the prospect of Cramer selling his bitcoin rather than expressing concern about the possible consequences for the market.
There has been no independent confirmation of how much bitcoin Cramer owns, or whether he has sold any of it. Although the Bitcoin blockchain records every transaction, it does not identify the person controlling a wallet unless that individual publicly links themselves to an address.
Bitcoin continued to trade without significant disruption. Its price was close to $63,764, representing a modest gain, while Strategy, the company formerly known as MicroStrategy, disclosed earlier that morning that it had sold about 1,638 BTC.
The technical concern raised by Cramer relates to the cryptography used to protect ownership of bitcoin. Every bitcoin address relies on a digital signature system called ECDSA, which is based on the secp256k1 curve.
A powerful enough quantum computer using Shor’s algorithm could theoretically calculate a private key from a public key. That would create a route to controlling funds held at vulnerable addresses.
The immediate risk is not identical for every bitcoin. It is greatest for addresses whose public keys have already been exposed through address reuse, older wallet formats, or the short period after a transaction is broadcast but before it has been confirmed.
The hardware needed to carry out such an attack has appeared less remote in recent years. A March 2026 paper from Google Quantum AI estimated that breaking the relevant cryptography could require fewer than 500,000 physical qubits about 20 times fewer than earlier estimates.
However, current quantum computers generally operate with hundreds to low thousands of physical qubits. Only a small number are considered sufficiently reliable logical qubits, which are the systems needed for meaningful attacks on cryptographic protections.
IBM’s demonstrations involving tens of logical qubits show that progress is being made, but also underline the amount of engineering still required before the technology reaches the necessary scale.
The potential impact is substantial. Researchers estimate that about 30% of bitcoin’s total supply roughly six to seven million BTC is held in addresses with exposed public keys. Much of that supply is believed to sit in early wallets that have not been touched for years.
Those dormant holdings pose a particular challenge because coins that are never moved are not transferred into newer address formats designed to offer greater protection.
There is no agreement among experts about when a quantum computer capable of compromising bitcoin’s security will exist. Krishna has referred to 2028 and 2029 as possible dates for measurable commercial effects at IBM, although he expects wider economic consequences to emerge later.
More cautious researchers place the arrival of a cryptographically relevant machine in the 2030s or even the 2040s. While the underlying risk is widely accepted, the timetable remains disputed. Cramer’s prediction of a threat within three years is therefore considerably earlier than most technical forecasts.
Cramer has changed his position on bitcoin several times. He sold during the 2021-22 downturn, later described the cryptocurrency as a hedge and has now indicated that he may reverse course again.
Those repeated changes have strengthened his reputation among traders as a market sentiment signal rather than a source of investment advice.
The next developments will include whether Bitcoin Core developers make progress on quantum-resistant proposals, whether Cramer confirms an actual sale and how Google’s and IBM’s quantum milestones compare with their public roadmaps.
For many observers, the debate is no longer simply about whether quantum computing poses a theoretical danger to bitcoin. The key question is whether quantum technology will mature before Bitcoin’s defences are upgraded.
