US IPO candidates are rushing to make the most of a short issuance window ahead of the launch of SpaceX’s mammoth IPO.

Several companies have launched or priced offerings in recent days in a clear push to access the market as conditions improve momentarily amid lower volatility and hopes for a resolution to the Iran war.

However, growing concerns about economic weakness, the broader impact of the war, and the anticipated scale of the transaction raises questions about how much capacity the market can absorb in June, when SpaceX’s IPO could suck the oxygen out of the market.

Arcline-backed aerospace company Arxis priced an upsized IPO this week and its stock jumped 36%, while industrial group Madison Air also carried out a listing and recorded a 16% rise in its share upon trading. Aerospace company AEVEX is due to price 16 April. Meanwhile, Pershing Square is on a two-week roadshow for its dual listing. Other names that have launched or are nearing it include X Energy, Yesway, Blackstone-backed events company Encore, and a few biotech companies.

Driven by concerns around the economic impact of the war and a market that may be under-pricing those risks, the US IPO pipeline is “accelerating, particularly among sponsors, because people are shooting to get out now,” one investor said, pointing to a growing sense of urgency among issuers. He added that the current market is being used opportunistically rather than reflecting full conviction in its durability. “The potential for weakness and a re-rate is high, so if you have a chance to get out now… you’re going to take that chance,” the investor said.

That urgency is now intersecting with a different constraint: the mechanics of executing alongside a transaction that could dominate both capital allocation and investor attention. Across the pipeline, companies are actively trying to position themselves ahead of SpaceX. “I think you will see an uptick of IPOs between now and early June, just for those that are rushing to get to market ahead of it,” a senior ECM adviser said. At the same time, the challenge is not simply timing, but how to navigate a transaction of a scale the market has not recently absorbed. “A lot of IPOs in the pipeline are trying to figure out how to do it,” he said.

That includes weighing whether to accelerate ahead of the deal, attempt to execute alongside it, or wait until after it, with each option carrying a different set of risks and execution trade-offs. In many cases, issuers currently on the sidelines are being advised to wait until SpaceX has started trading before launching their own transactions, particularly if they cannot clearly complete execution before the end of May.

The dynamic is driven not only by the size of the deal, but by how capital is likely to be allocated. At the scale being discussed, SpaceX is expected to command attention from large institutional investors, including funds that are effectively compelled to participate given its profile, potential index inclusion and the risk of underperformance relative to benchmarks if they do not. That creates an element of forced demand, with investors allocating capital not purely on valuation grounds but also to maintain exposure to a transaction that is likely to be widely owned.

This dynamic has not been tested at this scale in recent IPO markets, the senior ECM adviser said, increasing uncertainty around how both the deal itself and surrounding issuance will be absorbed. Some large long-only investors have indicated that they would prefer not to engage with other IPOs during the SpaceX marketing period, focusing instead on the flagship transaction. “We’ve been told by investors not to bring other IPOs during this period,” the senior adviser said, referring to conversations with large mutual fund complexes.

That feedback has direct implications for execution planning. For smaller IPOs, typically around USD 500m, allocation sizes are relatively limited, reducing the impact of any single large transaction. But for larger IPOs seeking multi-billion-dollar raises, the overlap in investor demand becomes more material. For those issuers, capacity constraints become more tangible, particularly if investors are already committing significant capital to SpaceX.

“If you can’t beat it to market, don’t flip,” the senior adviser said.

The risk is not limited to execution alongside the deal, but extends into what happens if companies misjudge timing. Once an issuer files publicly and does not proceed within the typical launch window, it can end up sitting publicly filed without launching, exposed to ongoing market scrutiny and repeated financial updates without execution, making it harder to maintain momentum and maintain investor confidence. The exposure can become self-reinforcing, particularly in volatile markets, where delays are quickly interpreted as weakness.

A risky calculus

There are two primary risks that could affect the outcome of the SpaceX IPO: excessive size, which could reduce aftermarket demand if investors are fully allocated in the deal; and valuation, particularly if institutional investors are unwilling to support pricing levels and more stock is allocated to retail investors. In that scenario, much of the demand could be satisfied in the initial allocation, leaving limited incremental buying in the aftermarket and increasing the risk of weaker trading performance. In turn, this could influence sentiment toward other IPOs coming immediately after.

“Could SpaceX break the IPO market,” the senior adviser said, clarifying that the risk is one of disruption rather than a complete halt in issuance. “That is also a possibility.”

Another IPO adviser said larger companies are more likely to feel the pressure from SpaceX, given their reliance on the same pools of capital, while smaller issuers are less directly exposed as they tend to appeal to a different segment of the market.

A listing exchange executive said the IPO pipeline remains the deepest since the 2019–2020 period, with a high number of filed and confidential submissions continuing to progress through the system. Many companies are continuing preparatory work while taking a wait-and-see approach to execution, focusing on improving margins, strengthening balance sheets and putting in place more robust financial reporting and controls. These companies are effectively getting their house in order, ensuring that they are ready to move quickly when a viable window emerges.

Broader headwinds remain in place, including weaker software valuations, further geopolitical tensions, and uncertainty around the trajectory of inflation and interest rates, which continue to influence investor sentiment. Access to private capital has reduced the urgency to list, allowing companies to delay transactions without immediate funding pressure while maintaining readiness.

In that context, SpaceX is acting as a focal point around which decisions are being made. Not all advisers, however, believe companies should fully anchor their strategy around SpaceX. “I don’t think you can fully dictate your life based on what Elon Musk is going to do,” said another senior adviser.

Investor appetite, they added, remains intact, but has become more valuation-sensitive. “It feels like the market is pretty good in terms of investor appetite. I think where it’s changed a bit because of volatility is just what is that value, what are you willing to pay,” this adviser said. “The long-onlies are like, well, I’ll make my decision, but I’ll make it at the last minute, rather than coming in early as an anchor.”

One ECM banker noted the breadth of industrial and sponsor-backed candidates currently preparing to list.

“If you have a real company, with a defensive equity story, people should want to invest in those companies. If the valuation is fair and it’s a business investors understand, that can still be on the road at the same time.”