Comfort Systems USA (FIX) is a national network of HVAC and mechanical services businesses that has shifted in recent years from steady contractor revenue to a faster-growing, cash-generative profile driven by per-share expansion and higher reported earnings.
The company shows marked per-share and earnings momentum: diluted EPS reached $38.64 (period end 2026-03-31) after a one‑year EPS gain of 95.7% (2025-12), while revenue per share rose to $252.50 (2025-12-31) with one‑year growth of 29.5%, illustrating EPS expanding faster than top‑line per share growth (EPS Diluted & Revenue per Share, Revenue & Net Income). Operating cash flow has climbed from $91.2M in 2016 to $849.1M (TTM, 2024-12-31), free cash flow margin stands at about 10.5%, and trailing ROE improved to 30.6% (2024-12-31), indicating meaningful cash generation and strong returns on equity (Earnings Quality Analysis, Return on Equity (ROE)).
There are areas of concern to monitor. Operating margin swung to -0.8% in 2025 even as gross margin improved to 24.1% and net profit margin was 11.2%, a divergence that reflects unusual operating volatility in the most recent year (Profit Margin Trends). Reported net income also accelerated to $1.39B (TTM, 2026-03-31) while the most recent operating cash flow datapoint is $849.1M (TTM, 2024-12-31), so net income currently exceeds the latest comparable OCF figure — a timing or quality mismatch worth watching (Earnings Quality Analysis). Capital deployment has intensified: investing cash flow moved to –$467.3M (TTM, 2025-12-31) and financing cash flow was –$263.2M (TTM, 2026-03-31), signaling larger investments and cash returns or paydowns in recent periods (Strategic Capital Allocation).
Key fundamentals to track going forward include continued revenue-per-share and diluted EPS trends and whether EPS growth is matched by operating cash flow; the trajectory of operating margin recovery toward prior levels; the evolving scale and purpose of investing cash outflows; leverage metrics (debt-to-equity ∼0.19) and the trend in the company’s P/E, which reached 35.7x most recently (Revenue & Net Income, Profit Margin Trends, Strategic Capital Allocation, Price-to-Earnings (PE) Ratio Trend, Return on Equity (ROE)).
The foundation of business quality and long-term value creation
COMFORT SYSTEMS USA INC's quarterly revenue exhibits pronounced seasonality with year-end quarters markedly larger than mid-year periods. Recent mid‑year revenues rose through 2025 (Q2 $2.17B to Q3 $2.45B) and jumped to $4.48B in 2025 Q4; 2024 Q4 was an even larger spike at $5.22B, while 2023 Q4 was $3.83B. These figures show material differences between Q4 and other quarters in each year.
Net income has moved higher over the past several years and shows a notable peak in late 2025. Quarterly net income climbed from $148.8M in 2023 Q4 to $242.2M in 2024 Q4 and reached $500.1M in 2025 Q4 before decreasing to $370.4M in 2026 Q1. The most recent quarterly revenue was $4.48B (2025-12-31) and the most recent quarterly net income was $370.4M (2026-03-31).
Why Growth Matters
Consistent revenue and earnings growth are the lifeblood of successful long-term investments. Companies that can grow their top line (revenue) and bottom line (net income) over many years demonstrate they have products or services customers value and are willing to pay for repeatedly.
Revenue Growth shows whether the company is expanding its market reach, gaining market share, or successfully launching new products.Net Income Growth demonstrates the company can convert that revenue into actual profits while managing costs effectively.
Look for steady, sustainable growth rather than erratic spikes. The best businesses compound earnings year after year, creating tremendous value for shareholders over time. Companies that can grow earnings faster than revenue are improving their profitability—a sign of operational excellence and competitive strength.
Year-over-year growth rates for revenue and earnings per share
Reading the Growth Rate Chart
This chart converts the absolute per-share figures into year-over-year percentage changes, making it easy to see whether growth is accelerating, decelerating, or reverting to trend — regardless of the company's absolute size.
Revenue per Share Growth (1-year, split-adjusted) measures how quickly the top line is expanding on a per-share basis. Sustained positive growth signals that the company continues to win customers and grow its addressable market.EPS Diluted Growth (1-year, split-adjusted) measures how quickly earnings are compounding for each shareholder. When EPS growth consistently outpaces revenue growth, operating leverage and margin expansion are at work.
Look for consistency, not just magnitude. A company that reliably grows EPS 10–15% per year is far more valuable than one that alternates between 50% spikes and deep contractions. Negative EPS growth during a period of positive revenue growth is a red flag — costs are rising faster than sales. Quarters where both lines converge near zero or go negative deserve close scrutiny.
How revenue converts to net income for the most recent annual period
Over the period Jan 2025 to Dec 2025, Comfort Systems Usa Inc converts approximately 24¢ of every revenue dollar into gross profit (gross margin: 24.1%).After accounting for operating expenses and taxes and expenses, the company retains 11.2% as net profit margin, resulting in $1.02B in net earnings.
Period Information
Report Type: Annual (10-K)
Period: Jan 2025 to Dec 2025
Analyzing long-term margin stability and competitive positioning
COMFORT SYSTEMS USA INC's gross and net margins show an upward trend into the most recent year. Gross margin increased from 21.0% for the 2024 period to 24.1% for 2025, and net profit margin rose from 7.4% in 2024 to 11.2% in 2025, reflecting higher retained revenue and bottom-line percentage in the latest reported period compared with the prior year.
Operating margin exhibits a clear inflection in the latest data: after single-digit operating margins through earlier years and a peak at 10.6% in 2024, operating margin fell sharply to -0.8% in 2025. This represents a pronounced swing in operating profitability in the most recent year. The latest observed values are Gross Margin 24.1%, Operating Margin -0.8%, and Net Profit Margin 11.2%.
Understanding Profit Margins
Between Jan 2025 and Dec 2025, Comfort Systems Usa Inc converts every dollar of revenue through the following stages:
Sustainable competitive advantages reveal themselves through consistently superior profit margins over extended periods. Companies with durable economic moats maintain pricing power and operational efficiency that competitors struggle to match.
A sign of durable competitive advantage is earning sustained higher margins than competitors.Look for margins that remain stable or improve over time, especially during economic downturns. Declining margins may signal increasing competition, pricing pressure, or deteriorating business fundamentals.
Comparing reported earnings to actual cash generation
COMFORT SYSTEMS USA INC’s trailing twelve-month net income shows a marked upward trend over recent years, rising from $112.9M in 2018 to $245.9M in 2022, $323.4M in 2023 and $522.4M at the 2024 year-end. The most notable inflection occurs after 2024, with net income increasing to $1.02B at 2025-12-31 and further to $1.39B at 2026-03-31, indicating a sharp acceleration in reported profitability in the most recent quarters.
Operating cash flow (TTM) is reported most recently at $849.1M for the period ending 2024-12-31, up from $91.2M in 2016, showing a long-term increase in cash generation though the latest available cash-flow datapoint precedes the recent surge in net income. As of the latest reported periods, net income ($1.39B) exceeds the most recent operating cash flow ($849.1M). The most recent Net Income (TTM) was $1.39B (period end 2026-03-31). The most recent Operating Cash Flow (TTM) was $849.1M (period end 2024-12-31).
The Earnings vs. Cash Flow Gap
Reported earnings (Net Income) doesn't always reflect actual cash generation. Companies use accrual accounting, which recognizes revenue when earned and expenses when incurred—not when cash actually changes hands. This creates timing differences and opportunities for accounting discretion that can mask underlying business health.
Net Income (the "earnings" number) can be influenced by non-cash items like depreciation, stock-based compensation, and changes in accounting estimates.Operating Cash Flow, however, shows the actual cash the business generates from its core operations—a harder number to manipulate.
Trailing Twelve Months
What to Look For
Key Insight: Companies with durable competitive advantages typically show operating cash flow that meets or exceeds net income over time, demonstrating they convert accounting profits into actual cash that can be returned to shareholders or reinvested in the business.
Measuring management's efficiency at generating profits from shareholder capital
COMFORT SYSTEMS USA INC's trailing twelve-month Return on Equity has risen in the most recent quarters, moving from 25.3% at 2023‑12‑31 to 30.6% at 2024‑12‑31, a 5.3 percentage‑point increase. The series shows a recovery after a low of 17.8% at 2021‑12‑31, with ROE generally climbing through 2022 and 2023 (23.2%–24.6%–25.3%) before the larger step up in 2024.
Over the full history shown (2018–2024), ROE has been above 20% for most periods, with exceptions at 2019 (19.5%) and 2021‑12‑31 (17.8%). The latest observed Return on Equity (period ending 2024‑12‑31) was 30.6%.
The Gold Standard of Profitability
Return on Equity (ROE) is a powerful measure of how effectively a company's management is using the money shareholders have invested. Calculated by dividing Net Income by Shareholders' Equity, it reveals how much profit is generated for every dollar of equity capital.
A consistently high ROE (typically above 15-20%) is often the signature of a "quality" business with a durable competitive advantage. It indicates that the company can generate high returns on its own capital, which it can then reinvest at these high rates to compound value over time.
What to Look For:
How the company generates and deploys its cash
COMFORT SYSTEMS USA INC shows a marked increase in operating cash flow over the available history, rising from $91.2M (TTM) in 2016 to $849.1M (TTM) reported for the period ending 2024-12-31.
Investing cash flow has moved toward larger outflows in recent years, shifting from -$97.2M (TTM) in 2022 to -$343.5M (TTM) by 2024-12-31 and further to -$467.3M (TTM) as of 2025-12-31, indicating progressively larger investing activity on a trailing twelve-month basis.
Financing cash flow turned from a positive $70.5M (TTM) in 2021 to sustained negative levels from 2022 onward (e.g., -$205.9M in 2022, -$298.6M in 2023), with the most recent reported TTM financing cash flow at -$263.2M as of 2026-03-31.
Latest observed values: Operating Cash Flow (TTM) $849.1M, Investing Cash Flow (TTM) -$467.3M, Financing Cash Flow (TTM) -$263.2M.
Understanding Company Strategy
Capital allocation refers to how management decides to spend and invest the company's cash. Analyzing the three primary categories of cash flow reveals a company's true operational strategy:
What to look for: Is the company bootstrapping (funding growth solely from operating cash)? Are they borrowing to fund aggressive expansion or dividends? Or are they capital raising by issuing new shares, potentially diluting your ownership? A healthy, mature company typically generates strong operating cash, moderately invests in growth, and returns the surplus to shareholders through financing activities.
Trailing Twelve Months
Net assets attributable to each share — the accounting floor of intrinsic value
Why Book Value per Share Matters
Book value per share is the net worth of the company — total assets minus total liabilities — divided by shares outstanding (split-adjusted). It represents the theoretical liquidation value per share if every asset were sold and every liability repaid at balance-sheet carrying values. It is the accounting foundation upon which much of equity valuation is built.
A steadily rising book value per share is one of the most reliable signals of compounding wealth creation. It means the company is retaining earnings and building net worth faster than it is returning capital or eroding it. Warren Buffett famously tracked Berkshire Hathaway's book value per share for decades as his primary measure of intrinsic value growth.
Context is essential. Asset-heavy businesses (banks, manufacturers, utilities) should be judged by book value more directly than asset-light businesses (software, consumer brands), where intangible assets like intellectual property and customer loyalty may far exceed their balance-sheet carrying values. A company trading at a large premium to book value is not necessarily overvalued — it may simply possess competitive advantages that accounting rules do not capture. Conversely, a declining book value per share — especially over multiple years — is a serious warning sign of capital destruction.
How much of the company is financed by debt versus shareholders' equity
Reading the Debt-to-Equity Ratio
The debt-to-equity (D/E) ratio compares total financial debt to shareholders' equity. A ratio of 1.0 means the company has borrowed one dollar for every dollar of equity; a ratio of 2.0 means it has borrowed twice as much as it owns. Financial leverage amplifies both returns and risk: in good times, debt turbocharges equity returns; in bad times, it accelerates losses and can threaten solvency.
Trends matter more than a single number. A rising D/E ratio can mean the company is taking on debt to fund growth — potentially value-creating if returns exceed the cost of capital. But it can also mean equity is being eroded through losses or that the business is borrowing simply to sustain operations. A falling D/E ratio generally reflects strengthening financial health: earnings are being retained, debt maturities are being paid down, or both.
Industry norms vary enormously. Capital-intensive sectors (utilities, real estate, financials) routinely carry high D/E ratios that would be alarming in, say, a technology company. Always compare against sector peers. As a rough rule of thumb, a D/E above 2× in a cyclical business warrants careful scrutiny of interest coverage and refinancing risk.
Short-term liquidity — can the company cover its near-term obligations?
Liquidity: Can the Business Pay Its Bills?
The current ratio is calculated as current assets divided by current liabilities. A ratio of 1.5 means the company has $1.50 of short-term assets — cash, receivables, inventory — for every $1.00 of obligations due within the next twelve months. It is the most direct measure of near-term financial resilience: can the business meet its obligations without needing to raise new capital or sell long-term assets at a discount?
A ratio above 1.0 is generally healthy, meaning current assets exceed current liabilities. A ratio consistently above 2.0 may indicate the company is holding excess cash or inventory that could be deployed more productively. A ratio below 1.0 is a warning sign — the company is relying on future cash generation or external financing to cover its near-term obligations, which is manageable in normal conditions but dangerous during a downturn.
Trends and context matter.A declining current ratio isn't always alarming — highly efficient businesses (e.g., large retailers with reliable daily cash flows) often run leaner balance sheets intentionally. Conversely, a rapidly rising current ratio can signal slowing sales causing inventory to build, or customers taking longer to pay. Always compare the trend against industry peers and cross-reference with the cash flow statement to assess whether the business is genuinely liquid or just holding non-cash current assets.
How much the market is paying for each dollar of company earnings
COMFORT SYSTEMS USA INC's trailing twelve-month P/E has trended upward over the last several quarters after a period of lower, more variable levels earlier in the series. The ratio moved from 17.2x at 2022-12 to 22.5x at 2023-12, then rose more sharply to 29.3x at 2024-12 and 32.9x at 2025-12, marking a clear inflection toward higher valuations beginning in 2023–2024.
The upward momentum continued into the most recent quarter, with the P/E reaching the highest value in the provided series. The most recent Price-to-Earnings (P/E) ratio was 35.7x.
What Is the PE Ratio?
The Price-to-Earnings (PE) ratio is one of the most widely used valuation metrics in investing. It divides the current stock price by the company's earnings per share (EPS), revealing how much investors are willing to pay for each dollar of earnings. A high PE can signal that the market expects strong future growth, while a low PE may suggest undervaluation—or reflect genuine concerns about the company's prospects.
Context matters:PE ratios vary significantly across industries. High-growth technology companies routinely trade at PE ratios above 30x or 40x, while mature, low-growth sectors like utilities or financials often trade closer to 10–15x. Always compare a company's PE to its own history and its industry peers, not just an absolute number.
What to Look For:
Key Insight:The PE ratio is a snapshot of market sentiment and expectations. Tracking it over time alongside earnings trends reveals whether the market's valuation has expanded or contracted—and whether that change is justified by fundamentals.