IonQ Just Announced a Major Breakthrough. Should Investors Buy the Stock Now?

Quantum computers have a real problem. Small errors slip into calculations all the time, and catching and fixing them fast enough has been a real issue for the industry. On Tuesday, Sept. 22, IonQ (IONQ +1.11%) said it may have found a solution to this problem. ExpandNYSE: IONQIonQPremium FeatureMoneyball Superscore62/100Today's Change(1.11%) $0.50Current Price$45.48Key Data PointsMarket Cap$18BMarket cap calculated using publicly traded shares outstanding only. Does not include unlisted, private, or dual-class non-traded shares. Implied market cap may vary.Day's Range$44.12 - $46.5552wk Range$25.89 - $84.64Volume27.6MAvg Vol21.3MGross Margin-3317.96% IonQ's statement said it has developed the industry's first end-to-end, real-time quantum error-correction decoder. Even better, this breakthrough runs on a single standard CPU. This gives IonQ a real edge in this highly competitive race. The day after the announcement, IonQ also said its Superion 256 will become the first on-premises quantum processor at Nvidia's (NVDA +0.22%) Accelerated Quantum Research Center. Image source: The Motley Fool. The stock price rose more than 11% on Wednesday, in line with the good news. IonQ remains a high-risk, speculative investment. In particular, the decoder was validated on simulated data rather than in a live system. How commercially viable quantum computing will be in the coming years remains to be seen. IonQ's valuation is also quite rich. It's deeply unprofitable as well. Investors interested in this space should recognize the sector's longer time horizon and volatility. Shares of IonQ have actually fallen more than 40% in the past year. For investors willing to stay invested for the next several years as this nascent sector finds its footing and use cases, this IonQ breakthrough is significant enough to consider buying the stock, in my opinion. Read NextSep 25, 2026 •By Parkev Tatevosian, CFAGreat News for IonQ Stock Investors!Sep 25, 2026 •By Chris NeigerRigetti, D-Wave, or IonQ: Which Quantum Stock Has the Best Shot at Survival?Sep 25, 2026 •By Johnny RiceIonQ Has Made Another Quantum Computing Breakthrough: Here's What a $1,000 Investment in It Could Look Like in 5 YearsSep 25, 2026 •By Will HealyBetter Quantum Computing Stock: Nvidia vs. IonQSep 25, 2026 •By Keithen Drury$500 Invested in IonQ Now Could 10x if Quantum AI Hits by 2029Sep 24, 2026 •By Keith SpeightsIonQ Cleared One of Quantum Computing's Biggest Hurdles.

Should You Buy the Stock?About the AuthorCatie Hogan is a contributing stock analyst and personal finance expert at The Motley Fool. She's the founder of the family finances newsletter, Cents of Humor. Previously, Catie was the Head of Advice & Coaching at Parthean, an Associate Financial Planner at Element Financial Group, and a Financial Advisor at Edward Jones. She holds a bachelor's degree in journalism from Emerson College, a master's degree from University of Nevada Las Vegas, and a Certificate in Financial Planning from Bryant University.TMFCatieHoganStocks MentionedIonQNYSE: IONQ$45.48(+1.11%)+$0.50Motley Fool Stock Advisor’s Latest PickGet Access---% Avg ReturnNvidiaNASDAQ: NVDA$225.07(+0.22%)+$0.49*Average returns of all recommendations since inception. Cost basis and return based on previous market day close.