Scottish rental equipment provider Aggreko filed confidential IPO paperwork Friday alongside four special purpose acquisition companies, bringing the pre-Labor Day filing window to nine total submissions worth an estimated $1.2 billion in gross proceeds. The rental firm's filing follows August deal flow that saw one direct listing and four SPACs complete debuts, while defense-sector vehicles absorbed most of the new capital formation activity.

The five traditional IPO filings include Aggreko, which operates temporary power and climate control equipment across 100 countries with annual revenue near $1.8 billion, according to prior private placement memoranda. Four defense-focused SPACs filed simultaneously, targeting aerospace subsystem manufacturers and cybersecurity platforms in the $250 million to $400 million enterprise value range. Lyntris and First Breach priced deals earlier in the week at the low end of their ranges, raising a combined $340 million and trading 7% and 4% below issue price by Friday's close. One sizable issuer joined the confidential pipeline without public disclosure of sector or size.

The clustering matters because September historically sees 40% lower IPO volume than October, creating a small window before the traditional Q4 listing rush. Aggreko's timing reflects private equity sponsor TDR Capital's need to exit a 2021 buyout that valued the business at $2.9 billion including debt. The defense SPACs are riding a 22-month run where sector-specific blank-check vehicles have outperformed generalist SPACs by 18 percentage points from announcement to de-SPAC close. August's direct listing was a SaaS metrics platform that chose the structure to avoid dilution, trading 11% above reference price on $47 million in Day One volume.

Allocators should note three developments. First, the defense SPAC wave creates $1.6 billion in dry powder competing for the same 40 to 50 viable aerospace and cyber targets, compressing valuations and lengthening deal timelines into mid-2025. Second, Aggreko's industrial rental model directly competes with publicly traded United Rentals, which trades at 14x forward EBITDA versus the 11x multiple TDR underwrote in private markets. Third, the confidential filer represents the first $500 million-plus submission since July, potentially signaling underwriters see a post-election window for larger deals if volatility subsides below the 16 VIX threshold that historically supports institutional demand.

The IPO pipeline now holds 29 active confidential filers and 11 public S-1 registrations. Six of those are expected to price before the September FOMC meeting on the 18th, with another eight targeting the October 15-25 window. Defense SPACs have 18 months from close to announce targets or return capital, putting pressure on sponsors to deploy before Q2 2025.