What ASP Isotopes Inc. told the SEC could break it.

ASP Isotopes has heavy customer concentration — two customers in its construction-services (Skyline) segment were 32.2% ($7.7M) and 13.7% ($3.3M) of consolidated revenue in 2025, and one isotope customer was 14% in 2024 — and it expects its QLE enriched-isotope business to depend on a limited number of customers (notably TerraPower) under long-term contracts; loss of a key customer would materially hurt revenue. (Construction customers not named, so the broader concentration is recorded here.)

“There were two customers in the construction services segment representing $ 7.7 million and $ 3.3 million, or 32.2 % and 13.7 %, respectively, o f the Company's consolidated revenues for the year ended December 31, 2025 .”

ASP Isotopes' enrichment plants are being constructed in South Africa, and its Renergen Virginia Gas Project and PET Labs radiopharmaceutical operations are also in South Africa (Free State Province), a region with poor socio-economic conditions (31.9% unemployment) that raise community/employment expectations and operational risk; this geographic concentration exposes the company to South African political, economic and currency risk (its Skyline construction arm operates in Hong Kong).

“Renergen's Virginia Gas Plant is located in the Free State Province of South Africa. South Africa's unemployment rate was 31.9% in the third quarter of 2024. Poor socio-economic conditions in these communities increase expectations for employment from businesses operating in these communities”

Uranium/lithium enrichment is among the most sensitive nuclear technologies — highly controlled, subject to export limits and public-disclosure restrictions — and ASPI's facilities require extensive regulatory approvals, permits and licenses; its radioisotopes may also be regulated by the FDA/Health Canada/EMA, and it faces evolving U.S. tariffs/IEEPA actions (a February 2026 Supreme Court ruling struck down certain IEEPA tariffs), creating multi-front regulatory risk.

“Enrichment is among the most sensitive nuclear technologies because it can produce weapons-grade materials, and our technology is highly controlled and subject to limitations on public disclosure or export.”

ASP Isotopes depends on a limited number of third-party suppliers for components needed to construct the centrifuges and equipment for its South African enrichment plants, and the isotope supply chain is fragile — Russia has historically been the sole supplier of carbon-14 (used as a pharmaceutical/agrochemical tracer) with inconsistent service — so a material interruption in components or feedstock could prevent or delay its development programs.

“We depend upon a limited number of third-party suppliers for certain components required to construct the centrifuges and other equipment for the enrichment plants that are being constructed in South Africa.”