IBM's stock has its best day since January, and quantum is a big reason why

By Britney Nguyen and Emily Bary

A soon-to-be-published IBM paper discusses progress made in the realm of quantum error correction when using an AMD chip

IBM is known for a lot of different technologies, but its quantum efforts have been getting more attention.

Shares of International Business Machines Co. enjoyed their best day since January as optimism built around the company's quantum-computing efforts.

IBM (IBM) announced a plan back in June to build what it calls "the world's first large-scale, fault-tolerant quantum computer" by 2029, setting a path toward practical and scalable quantum computing.

And on Friday, Reuters reported that the algorithm IBM said it had developed to enable error correction can run on chips made by Advanced Micro Devices Inc. (AMD), according to an IBM research paper reviewed by the publication.

MarketWatch has since reviewed the paper, which cited "high accuracy and state-of-the art per-cycle decoding times" when running the algorithm on a field-programmable gate array chip from AMD.

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"IBM's demonstration of a breakthrough quantum error-correction algorithm working with readily available AMD classical hardware is a milestone in our clear path to building IBM Quantum Starling, the world's first large-scale, fault-tolerant quantum computer by 2029," an IBM spokesperson said.

The company added that "designing and implementing a way to do this at scale, and without requiring expensive GPU clusters, is a significant achievement to scaling useful quantum computers."

Jay Gambetta, who heads IBM's research, told Reuters that not only has IBM's algorithm been proven to work, but that it can do so on a chip from AMD that is already available and not "ridiculously expensive." He added that "showing that the implementation is actually 10 times faster than what is needed is a big deal."

AMD didn't immediately respond to a request for comment from MarketWatch.

IBM's stock rose 7.9% on Friday to log its best single-day performance since a 13% rally in January, according to Dow Jones Market Data. And with the shares closing at $307.46, they scored their first new record closing high since June 30, when they closed at $294.78.

Meanwhile, AMD's stock advanced 7.6%, powering the company past a $400 billion market capitalization.

The topic of quantum computing has been hot this year, as shares of smaller, pure-play companies have rallied on hopes that the technology is nearing a breakthrough moment. Shares of players like D-Wave Quantum Inc. (QBTS) and IonQ Inc. (IONQ) have staged two-day rallies on the heels of a Wall Street Journal report saying the U.S. government was considering stakes in the companies, though a White House representative since denied that discussions were taking place.

See also: Quantum stocks are rising. Why they may be the Trump White House's next investment.

IBM is a technology giant worth nearly $300 billion, and its business touches on many areas, from mainframes to software to consulting. Quantum isn't meaningful to the company from a financial point of view, but the company's work in the arena has generated interest on Wall Street.

Following IBM's announcement of a quantum development with HSBC last month, Evercore ISI analyst Amit Daryanani said the technology represents an "underappreciated catalyst that can help IBM stock keep rerating," or fetching a higher valuation multiple.

The company "has a $1 billion order book on quantum compute that we think will accelerate over the next three to four years," he added in a note to clients. IBM's work with HSBC was perhaps the first instance of "an empirical demonstration that current quantum computers (IBM's Heron processor) can provide measurable business value in financial markets," according to Daryanani.

-Britney Nguyen -Emily Bary

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10-24-25 1702ET