The return is higher than the $1.5bn that was estimated when the quantum company filed for its IPO a little more than three weeks ago.

Quantum computing company Quantinuum has raised $1.68bn in its US initial public offering (IPO), with 28m class A common stock shares to begin trading for $60 each on the Nasdaq Global Market today (4 June).

The return is higher than was estimated after the US company filed for its IPO a little more than three weeks ago, when reports suggested that an offering could raise more than $1.5bn for the Honeywell International-backed Quantinuum and value it at as much as $20bn.

Bloomberg reported that the offering, which was increased from an anticipated 26.5m shares and priced above its marketed range of between $53 and $55 per share, values the company at $15.6bn.

Quantinuum said it had granted underwriters a 30-day option to purchase up to an additional 4.2m shares of its class A common stock “to cover over-allotments at the initial public offering price, less underwriting discounts and commissions”. JP Morgan and Morgan Stanley are acting as “joint lead active book-running managers” for the IPO.

Quantinuum is one of seven quantum computing companies and two quantum foundries in the US to be recently allocated a share of $2bn in federal incentives under the CHIPS and Science Act after it signed a letter of intent for $100m to fabricate low-loss integrated photonics and specialised optical components tuned to trapped-ion critical wavelengths.

The company plans to partner with GlobalFoundries for critical semiconductor components and Monarch Quantum for integrated photonics.

The UK-founded, Colorado-based Quantinuum produces full-stack quantum platforms with commercially deployed systems. Its products are used by businesses across sectors including pharmaceuticals, materials science, financial services and governments, according to the company, which has multiple sites in the US, as well as a presence in the UK, Germany, Japan, Qatar and Singapore.

A recent McKinsey report found that quantum computing could create as much as $2.7trn in economic value by 2035. It said that quantum companies generated more than $1bn in revenue in 2025 – a number which could compound to as much as $4.4bn by 2028.

Last week, computing giant IBM said it would invest $10bn in the quantum field over the next five years.

In Europe this week, French quantum start-up Quobly raised €115m in Series A funding, while Finnish quantum player IQM upsized its ‘private investment in public equity’ financing to more than $146m ahead of a planned SPAC merger and US stock market listing.

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