Stocks in the quantum computing industry went all over the place in March. According to data from S&P Global Market Intelligence, D-Wave Quantum (QBTS 2.16%) rose 38.7%, and Quantum Computing (QUBT 5.28%) gained 31.9%. At the same time, shares of Rigetti Computing (RGTI 12.29%) fell 6.4%, and IonQ (IONQ 10.39%) took a 10.2% price cut.

It was a busy month, for sure:

• Three of these stocks reported earnings in March.
• There was a high-profile industry conference with market-moving implications.
• D-Wave announced an important achievement in its technology research.

D-Wave's technical achievement versus weak financial reports

Let's start with the biggest gain. On March 12, D-Wave said it had applied its annealing quantum computing systems to solve "a useful, real-world problem." The company's PR department laid it on thick, citing a "landmark" paper that "unequivocally validates" this industry-first achievement.

The company announced earnings the next day. Sales were flat year over year, and net losses under generally accepted accounting principles (GAAP) shrank from $0.60 to $0.15 per share.

Together with D-Wave's suddenly useful technology, investors embraced these results with open arms. The stock soared 92% in three days, pulling the rest of the industry along for a bullish ride.

By contrast, Rigetti and Quantum Computing posted quarterly results far below analyst expectations. Rigetti's fourth-quarter sales fell 33% year over year, multiplying the net losses from $0.09 to $0.68 per share. Quantum Computing posted 17% lower sales and 35% higher operating costs. Net losses increased from $0.09 to $0.47 per share in the fourth quarter. These reports didn't move Quantum Computing stock very far, though.

Nvidia stole the thunder of Quantum Computing's report by hosting a "quantum day" at the GTC technology conference at the same time. CEO Jensen Huang used that stage to apologize for his earlier analysis of the quantum computing industry placing real-world usage roughly 20 years into the future.

Investors didn't really buy that apology, resulting in unusually high volatility among quantum stocks on March 20.

This industry has a long (and time-consuming) way to go

D-Wave's "quantum supremacy" moment might have lifted the whole sector in March, like Alphabet's error-correcting progress that boosted this sector in November 2024. But the quality of that achievement quickly came under fire, as Scientific American noted that researchers had essentially refuted D-Wave's research paper in March 2024, during the peer-review process.

The quantum simulation of magnetic materials would reportedly take millions of years on a digital computer, but a new algorithm did the job on a normal laptop in two hours.

So it wasn't surprising to see the earlier price gains fade out to some degree. Still, the pure-play quantum computing stocks are floating on high hopes right now. All four of those pure-play quantum computing experts under my lens have at least tripled in the last six months. The gains of sector leader IonQ are less speculative than those of its smaller and riskier peers, but it's still a big jump based on more PR spin than actual progress:

QUBT data by YCharts.

Long story short, the quantum computing space has been overheated since Alphabet's Willow announcement. The stocks in this field should continue to trend lower as this speculative trend cools off.

Quantum computing will probably disrupt many industries and change how you think about computers in the long run, but it's much too early to pick long-term winners in this race. Please keep your pure-play quantum computing investments small enough that you could stand them going to zero.

Alternatively, you might want to lean on true tech giants like Alphabet and Nvidia instead. Almost every name in the "Magnificent Seven" club is deeply invested in quantum computing research. This way, you get exposure to the opportunity -- as a side dish to a trillion-dollar tech titan's world-class business.