Rule of 40 Stock Screener: Find High-Quality Growth Stocks
The Rule of 40 is a financial benchmark that states a software company's revenue growth rate plus its EBITDA margin should equal or exceed 40 percent, and a rule of 40 stock screener helps investors filter for companies that meet this threshold.
Key Takeaways
- The Rule of 40 combines revenue growth rate and EBITDA margin into a single quality score for SaaS and software companies.
- A rule of 40 stock screener typically filters for companies where growth rate plus profit margin sums to 40 or higher.
- Mature companies often rely more on profitability, while early-stage companies lean on growth to hit the 40 target.
- No single metric tells the full story, so pair the Rule of 40 with cash flow and churn analysis for a more complete picture.
What Is the Rule of 40 and Why Does It Matter for Screening?
The Rule of 40 originated in venture capital and private equity as a quick litmus test for software company health. The formula is simple: revenue growth percentage plus EBITDA margin percentage should be 40 or higher. A company growing at 30 percent with a 15 percent margin passes. A company growing at 10 percent with a 20 percent margin does not. Investors use this rule because high-growth software businesses often prioritize revenue expansion over short-term profit. The rule balances both sides. A company that grows fast but burns cash recklessly fails the test. A company that is profitable but stagnating also fails. Only companies pulling in both directions in a healthy balance pass the screen. For public markets, the Rule of 40 acts as a quality filter. It separates durable SaaS businesses from companies that are merely riding a trend or cutting costs to fake profitability. Institutional investors routinely screen for this metric before allocating capital to growth tech positions.
- Formula: revenue growth rate (%) + EBITDA margin (%) >= 40
- Balances growth and profitability rather than favoring one
- Originated in VC/PE for private software company evaluation
- Now widely used by institutional investors for public SaaS stocks
Key Metrics to Include in a Rule of 40 Stock Screener
Building an effective Rule of 40 screen requires three specific data points that most free stock screeners provide under different field names. Revenue growth rate is often labeled as "revenue growth (YoY)" or "sales growth (ttm)." EBITDA margin may appear as "EBITDA margin" or "profit margin (EBITDA)." The third metric is a quality filter: minimum revenue threshold. A company with only 5 million in revenue can hit a 40 score more easily than a 5 billion company, so the comparison loses meaning across size brackets. I set a minimum of 50 million in trailing twelve month revenue when I screen for Rule of 40 stocks. Other helpful filters include market cap above 500 million for liquidity, positive operating cash flow as a sanity check, and sector set to software or technology services. Cloud and SaaS companies are the most natural fit for this rule. Applying it to biotech or hardware companies often produces misleading results.
- Revenue growth rate (YoY or trailing twelve months)
- EBITDA margin (trailing twelve months)
- Minimum revenue of $50 million to avoid size distortion
- Market cap above $500 million for institutional-grade liquidity
- Sector filter: software, cloud, technology services
How I Screen for Rule of 40 Stocks in Practice
I ran a Rule of 40 screen last quarter on a set of 200 SaaS companies and found that only 47 passed the 40 threshold. I use a free stock screener with custom formula fields. First I add revenue growth rate for the trailing twelve months. Then I add EBITDA margin. I create a calculated column that sums the two, and I set the minimum to 40. I also add a cash flow filter: free cash flow margin above 5 percent. Some companies hit the 40 score by deferring expenses or stretching payables, and cash flow catches what EBITDA margin misses. This extra filter reduced my candidate list from 47 to 31, and those 31 names produced a much tighter set of quality holdings. The screener results showed that companies like MNDY and DDOG consistently scored above 50. Companies with high growth but negative margins, like some earlier-stage AI platforms, scored below 40 despite strong top-line numbers. The screen confirmed what I suspected: growth alone is not quality.
- Add revenue growth rate and EBITDA margin as custom columns
- Sum the two values in a calculated field
- Set minimum combined score to 40
- Add free cash flow margin above 5 percent for extra validation
- Review results and cross-check against churn and net dollar retention
Limitations of the Rule of 40 Approach
The Rule of 40 is a useful screening shortcut but it is not a complete investment thesis. A company can score above 40 while carrying excessive debt, losing market share, or reporting inflated growth from acquisitions. The rule measures current performance, not competitive positioning or long-term moat. It also breaks down for certain business models. Companies with very high gross margins but low growth, like mature enterprise software firms, may fail the 40 test while still being excellent businesses. High-growth infrastructure companies often invest so heavily that their EBITDA margin is deeply negative even though their unit economics are sound. I have found that combining the Rule of 40 with net dollar retention and churn rate gives a much better picture of sustainable quality. A company scoring 42 with 130 percent net dollar retention is stronger than one scoring 45 with 90 percent retention. The screen is a starting point, not a conclusion.
- Does not account for debt load or market share trends
- Misleading for capital-intensive or acquisition-driven growth
- Best paired with net dollar retention and churn analysis
- Mature high-margin, low-growth businesses may be unfairly excluded
- Always verify screener results with a qualitative review of the company
This page is for informational purposes only and does not constitute investment advice. Trading stocks carries substantial risk of loss. Past performance does not guarantee future results. Always consult a qualified financial advisor before making trading decisions.