ONT — Onterris, Inc. (formerly Montrose Environmental Group) · 2026-09-06 · Verdict: WATCH · Conviction 3

Price $17.85 (screen row in universe_under2b.csv, built 2026-09-06; no live quote available) · Mkt cap $627M · EV ~$993M · EV/EBIT 85x on FY2025 GAAP EBIT of $11.7M (8.4x 2026 guided Adjusted EBITDA) · FCF yield 14.5% trailing / ~5.6% forward · Net debt $366M incl. finance leases · ADV $11.2M Sources read: 10-K 2026-02-26 (Items 1, 1A, 7), 10-Q 2026-08-06, DEF 14A 2026-03-24, 8-Ks 2026-04-21, 2026-05-06, 2026-05-11, 2026-08-05, 2026-08-10, Form 4s (trailing 12m). No conference call transcript or prepared remarks were filed as an exhibit; the bundle's "transcript" file is the Q2 press release (EX-99.1, 2026-08-05).

1. What the business actually does

Onterris sells outsourced environmental compliance work. Labs and field teams test air, water and soil (Measurement and Analysis, 29.6% of 2025 revenue); consultants and engineers handle assessments, permitting, emergency spill response and contaminated water and soil treatment (one Consulting and Treatment segment from Q1 2026) (10-K 2025, Item 1; 10-Q Q2 2026, Item 2). Regulation makes the spend largely non-discretionary and 96% of 2024 revenue repeated in 2025 (10-K 2025, Item 1). Built by 70-plus acquisitions since 2012; rebranded from Montrose Environmental Group on April 17, 2026 (8-K 2026-05-06).

2. Why it is mispriced — the edge case

A real, identifiable trough, not a broken business. Q2 2026 revenue fell $47.9M to $186.7M, of which $37.7M was emergency response, against a prior-year quarter containing $53.6M from a single event that did not recur; core consulting grew $3.5M and Adjusted EBITDA margin rose to 17.1% from 16.9% on 20% less revenue (10-Q Q2 2026, Item 2; EX-99.1, 2026-08-05). The screen's 14.5% FCF yield comes from FY2025 operating cash flow of $107.5M (10-K 2025, Item 7), itself a product of that same emergency plus a $55.2M working-capital swing, so the boom and the apparent cheapness both trace to one incident.

Sellers are momentum and growth holders reacting to two guidance events in three months, plus a rebrand and ticker change that broke screen continuity; the stock is down 48.5% over twelve months (universe_under2b.csv). Someone is buying, though: on August 5, 2026 the board adopted a one-year rights plan "in response to significant and undisclosed accumulation of Onterris shares and derivative securities" and announced a strategic review including "evaluating acquisition interest in the Company" (EX-99.1, 2026-08-05; 8-K/A 2026-08-10). So the edge is half fundamental trough, half control contest, and I cannot underwrite the second half.

3. Unit economics and growth

FY2025 revenue was $830.5M, up 19.3%, with 12.7% organic growth (10-K 2025, Item 7). Segment Adjusted EBITDA of $169.1M less $52.9M of corporate cost gives consolidated Adjusted EBITDA of $116.2M, a 14.0% margin. GAAP income from operations was $11.7M, H1 2026 was $0.4M, and the company has lost money every year since inception, with a $273.5M accumulated deficit (10-K 2025, Item 1A; 10-Q Q2 2026). Goodwill of $465.8M and intangibles of $113.6M against $430.3M of book equity leave tangible equity deeply negative (EX-99.1 balance sheet, 2026-08-05).

The gap between $116M of Adjusted EBITDA and $12M of GAAP EBIT is mostly stock compensation and amortization. Stock compensation was $18.7M in H1 2026 alone, down from $24.6M a year earlier but still roughly $37M annualized against $118.5M of guided Adjusted EBITDA (EX-99.1, 2026-08-05). Concentration is real: the largest client was 17.8% of 2025 revenue (10-K 2025, Item 1).

4. Balance sheet and capital allocation

Total debt was $349.0M at June 30, 2026, up $60.8M in six months, against $12.7M of cash and $148.1M of revolver availability; H1 operating cash flow was negative $5.5M, worsened by a $27.7M bonus payment for 2025 outperformance (10-Q Q2 2026, Item 2). Credit-facility leverage was 3.2x versus a guided ~2.5x at year end (EX-99.1, 2026-08-05). The facility carries maximum leverage and minimum fixed-charge covenants, but the thresholds are not disclosed in the documents available here (10-K 2025, Item 1A).

The $40M buyback authorized May 7, 2025 sat unused through year end (10-K 2025, Item 7), then $30.0M went out in H1 2026 for 1,627,763 shares at an average of $18.42, above today's price, cutting share count 2.3% to 35.11M (EX-99.1, 2026-08-05). Insiders bought after the derating: CFO Allan Dicks 6,535 shares at $15.36 on 2026-05-11, director Peter Graham 30,000 shares at $15.94 to $17.19 in early June (Form 4s, 2026-05-12, 2026-06-08). Trailing twelve-month activity is still net selling of $2.3M, but every sale was a March option-exercise-and-sell at $25 to $30 (form4_last12m.csv). Directors and officers hold 10.4% (DEF 14A 2026-03-24).

5. Management: what they said vs what they did

On May 6, 2026 the CEO called Q1 weakness "transitory" and said "our full year outlook is unchanged," reiterating $840M to $900M of revenue and $125M to $130M of Adjusted EBITDA (EX-99.1, 2026-05-06). Three months later revenue was cut to $740M to $790M and Adjusted EBITDA to $117M to $120M (EX-99.1, 2026-08-05), so that reiteration was wrong by about $105M at the midpoint, and the May plan to "restart smaller, bolt-on and highly accretive acquisitions" became $30M of revolver-funded buybacks instead. They did deliver on cost: the margin guide went up, to 15.5%. But the implied H2 2026 figures are $68.8M of Adjusted EBITDA on roughly $410M of revenue, a 16.8% margin versus 13.8% in H2 2025 on only 2% less revenue. That 300 basis point step-up is the load-bearing assumption in the guidance.

6. Valuation

Common to all cases: 35.0M shares, no acquisitions, stock compensation charged as a real cost ("cash EBITDA"), 2027 basis. - Base (50%): revenue $800M as emergency response normalizes toward the 2024 level of $48M (10-K 2025, Item 7), 16.0% margin = $128M less $32M stock comp = $96M at 11.0x, less $330M net debt = $20.75. - Bear (30%): emergency response stays at the 2026 run-rate, revenue $760M, 15.0% margin = $114M less $35M stock comp = $79M at 9.0x, less $340M net debt = $10.60. - Bull (20%): a sale at 11x forward Adjusted EBITDA of $125M, less $340M net debt = $29.60. Probability-weighted value is about $19.50 against $17.85, roughly 9% upside, which is not enough margin of safety.

Reverse DCF: at $17.85 the enterprise is $993M, and charging the guided $118.5M of 2026 Adjusted EBITDA for roughly $37M of stock compensation, $25M of capital spending including finance-lease principal and about $8M of cash taxes leaves roughly $49M of unlevered free cash flow, so at a 9% discount rate the price implies about 4% perpetual growth, precisely the 4.0% CAGR EBI projects for the US environmental market through 2028 (10-K 2025, Item 1). You are not being paid for the emergency-response option.

7. Catalysts and timeline

Q3 2026 results in early November, guided to $190M to $210M of revenue at a 17% to 18% margin, is the first check on the H2 margin step-up. FY2026 results in late February test the $70M to $80M of second-half operating cash flow and ~2.5x year-end leverage. The review has no timetable; the rights plan expires August 4, 2027, which loosely bounds it. A Schedule 13D would be the cleanest signal.

8. Risks and pre-registered kill criteria

The structural risk: a 14-year, 70-acquisition roll-up that still produces almost no GAAP operating profit, carries 3.2x leverage and negative tangible equity, and pays roughly a third of Adjusted EBITDA in stock. Kill criteria: 1. Credit-facility leverage ratio above 3.0x at December 31, 2026 (company guides ~2.5x). 2. FY2026 operating cash flow below $60M, versus the implied ~$71M from 60% conversion of guided Adjusted EBITDA. 3. A third cut: FY2026 Consolidated Adjusted EBITDA below $117M, or Q3 Adjusted EBITDA margin below 17.0%. 4. Strategic review concludes with no transaction while annualized stock compensation stays above $30M. Conversely, a signed transaction, a 13D, or year-end leverage at 2.5x with positive full-year free cash flow would move this to IDEA.

9. Verdict and one-paragraph summary

WATCH, conviction 3. Onterris is a genuine, identifiable trough: essentially the whole revenue decline is one enormous 2025 environmental emergency that did not repeat, core consulting is still growing, and margins expanded through the downturn, which is why the company cut revenue guidance by $105M while raising its margin guide. But the screen's cheapness is an artifact. The 14.5% FCF yield is FY2025's emergency-driven cash flow, and once you charge the guided $118.5M of Adjusted EBITDA for roughly $37M of stock compensation and $25M of capital spending including finance leases, the enterprise trades near 20x unlevered free cash flow, implying about 4% perpetual growth, which is just the industry growth rate. Leverage is 3.2x against a 2.5x target, first-half operating cash flow was negative, and the guide rests on a 300 basis point second-half margin step-up from a team whose May reiteration was wrong by $105M. What keeps it alive is the rights plan against an undisclosed accumulator, a review that explicitly includes selling the company, and open-market buying by the CFO and a director. Wait for the Q3 print or a 13D rather than paying up for the review.

Research for discussion, not investment advice. Positions and sizing are the reader's decision.