Onterris, Inc. (ONT) stock intrinsic value fair value estimate & owner earnings analysis

Montrose Environmental Group is a fixed-price environmental services business with three segments: Assessment, Permitting and Response (scientific consulting and emergency spill and disaster response), Measurement and Analysis (environmental measurement and laboratory analysis) and Remediation and Reuse (including water treatment). 2025 revenue was $830.5 million, of which $678.4 million came from the United States, $120.8 million from Canada and $31.4 million from other countries. What the shares are worth rests on owner earnings: cash from operations, minus timing swings in working capital, minus stock compensation (a real cost we deduct even though it is not paid in cash), minus the capital spending needed just to stand still. On that basis the company earned about $37.0 million in 2025 ($1.05 per share), after losing about $21.5 million in 2024 (-$0.65 per share), $15.5 million in 2023 (-$0.52) and $18.1 million in 2022 (-$0.61). Earlier the business was smaller: 2021 was +$1.35 per share and 2020 +$0.50, but stock compensation was only $10.3 million in 2021 and $4.8 million in 2020, against $42.7 million to $64.7 million a year since 2022, so those years do not describe the business as it now runs. The 2025 jump is not a new run rate. The company reports that its largest client, 17.8% of revenue, included about $112.2 million of emergency and non-emergency response revenue stemming from a single environmental incident. Without it revenue would have been about $718 million, roughly 3% above 2024's $696.4 million. Emergency response revenue was $77.0 million in 2025 against $48.0 million in 2024, and three customers made up 56.9% of the Assessment, Permitting and Response segment. In the first half of 2026 revenue fell to $355.2 million from $412.4 million a year earlier (down about 14%), the second quarter alone was $186.7 million against $234.5 million, cash from operations was negative $5.5 million against positive $27.4 million, and the net loss was $11.3 million. Those results are consistent with the incident work fading. Our starting level for owner earnings is therefore about $0.20 per share (roughly $7 million). We reached it by taking the two years that reflect today's cost structure. 2024, once roughly $22.5 million of extra stock compensation tied to cancelling executive stock appreciation rights is set aside, was close to breakeven, about $0.03 per share. 2025, after removing our estimate of the incident's contribution (about $24.7 million, using the roughly 22% margin of the response segment), was about $0.35 per share. The $0.20 is the midpoint. The year-by-year results also carried cash earn-out payments to acquired companies ($19.5 million in 2022, $15.6 million in 2021) that we did not adjust in the reported figures, and a $12.2 million replacement aircraft in 2023. Growth in owner earnings from 2024 to 2025 was a swing from about -$21.5 million to +$37.0 million, which largely reflects the incident, so we do not carry it forward: the first year of every case starts from the normalized level with no growth. Base case, about $3.20 per share. Owner earnings of about $0.20 grow 3% a year for ten years, then stay flat for fifteen more years and are then worth nothing. The 3% is below the organic growth the company reported in 2025 in its Measurement and Analysis segment (5.4%) and its Remediation and Reuse segment (4.7%), driven by state regulatory requirements and cross-selling; 62.1% of revenue came from clients buying more than one service. We credit that continuing organic growth only. We do not credit new acquisitions (none were made in 2025, and earlier ones were paid for with borrowings and share offerings rather than from the business's own cash flow), margin gains, new products such as PFAS treatment, or any repeat of the 2025 incident. The flat years reflect decades-old client relationships and non-discretionary, regulation-driven demand, but we do not assume growth after year ten. Bear case, about $0.20 per share. The incident work does not repeat and results settle back to the 2022-2024 pattern, where owner earnings were close to zero once one-time items are set aside: about $0.03 per share, with no growth, for ten years and then nothing. Debt is meaningful: about $288 million of long-term debt, $32 million of finance leases and $17.6 million of unpaid acquisition earn-outs at the end of 2025, with $17.9 million of interest paid in 2025. The Series A-2 preferred stock was fully redeemed in 2025, so its dividends ($11.1 million in 2024) no longer drain cash. The company also recorded a $4.9 million bad-debt expense in 2025 on receivables from the City of Tustin, California, a large government project whose receivable, together with higher fourth-quarter revenue, contributed to a $42.0 million increase in receivables in 2024. Bull case, about $6.40 per share. The company's own levers execute: the 2025 level excluding the incident, about $0.35 per share, proves sustainable, grows 5% a year for ten years (in line with the 5.4% and 4.7% organic rates above), stays flat for fifteen more years and then ends. This does not assume another incident, higher margins or acquisitions. Judgements that matter. Working-capital swings are removed, but working capital has consumed cash in most years as the company grew, so our figure is more generous than raw operating cash flow in those years. The 2024 receivable that was later written off was in that removed amount, so the 2024 figure may understate the true cash cost. Payments on finance leases (about $11.1 million in 2025) sit outside operating cash flow and act like equipment spending, so our level is likely somewhat generous. Non-cash charges, including amortization of acquired intangibles (depreciation and amortization was $50.9 million in 2025), are added back as sunk acquisition cost, but because that asset base wastes away, we carry no growth from acquired businesses. Growth spending was estimated at 2.5% of each year's revenue increase; the rest of equipment spending is treated as maintenance. What would make this wrong: a further large incident-type contract or a step change in margin would make the bull case too low, while continued declines in first-half 2026 revenue and cash flow, or additional bad debts on government work, would move the value toward the bear case. The filings do not explain what part of the incident's profit was retained, so the $24.7 million is our estimate rather than a reported figure.