Methodology

What is in it

The MWC Quantum Index tracks pure-play quantum companies listed on a stock exchange. Pure-play means quantum technology is the company's main business. Large technology groups with a quantum division are left out, because their share price mostly reflects other activities.

It holds 14 companies today: IonQ (IONQ), Quantinuum (QNT), Rigetti Computing (RGTI), D-Wave Quantum (QBTS), Infleqtion (INFQ), IQM Quantum Computers (IQMX), Quantum Computing Inc. (QUBT), Pasqal (PSQL), Xanadu (XNDU), Horizon Quantum (HQ), SEALSQ (LAES), Arqit Quantum (ARQQ), BTQ Technologies (BTQ), Quantum eMotion (QNC).

How it is weighted

By full market capitalisation: the share price multiplied by the number of shares outstanding. A company worth twice as much as another moves the index twice as much. There is no cap on a single company's weight.

How the level is calculated

Add up the market capitalisation of every constituent, in US dollars, then divide by a fixed number called the divisor. The divisor was set so that the index stood at 1,000 on Jan 2, 2026. A level of 1,200 means the companies in the index are worth 20% more than on that date.

level = sum of (price x shares) / divisor

The daily change compares the same sum at the latest prices with the sum at the previous close.

When the divisor changes

When a company is added or removed, or when a company's share count changes, the total market capitalisation jumps for a reason that has nothing to do with prices. The divisor is adjusted at the same moment so that the level does not jump. The index only moves when prices move.

Where the numbers come from

Share counts come from each company's latest filing. Prices come from a market data provider and can be delayed. Outside regular trading hours the level uses pre-market or after-hours prices when the provider has them, and the page says which session the value is from. If a company's price is missing for a moment, the page keeps the last complete value and says which price is missing. No level is calculated when fewer than half of the companies have a price.

The S&P 500 line on the chart is the daily closing level of that index, from the same market data provider. The comparison shows how much each line has moved, in percent, since the first day of the time span you choose.

The list of constituents and their share counts was last updated on Nov 11, 2026.