MKL vs MMC vs AON vs ERIE

For growth investors, Aon plc (AON) is the stronger pick with 9.

4% revenue growth year-over-year, versus -1. 0% for Markel Corporation (MKL). Markel Corporation (MKL) offers the better valuation at 10. 6x trailing P/E (16. 0x forward), making it the more compelling value choice. Analysts rate Aon plc (AON) a "Buy" — based on 38 analyst ratings — the highest consensus in this comparison. The "better buy" depends entirely on your goals: growth investors should weight revenue trajectory, value investors should weight P/E and PEG, and income investors should weight dividend yield and streak.

On trailing P/E, Markel Corporation (MKL) is the cheapest at 10.

6x versus Marsh & McLennan Companies, Inc. at 21. 3x. On forward P/E, Markel Corporation is actually cheaper at 16. 0x. The PEG ratio (P/E divided by earnings growth rate) is the most growth-adjusted single valuation metric: Markel Corporation wins at 0. 64x versus Erie Indemnity Company's 1. 26x — a PEG below 1. 0 traditionally signals the market is underpricing earnings growth.

Over the past 5 years, Markel Corporation (MKL) delivered a total return of +47.

5%, compared to +14. 8% for Erie Indemnity Company (ERIE). Over 10 years, the gap is even starker: AON returned +219. 8% versus MKL's +89. 3%. Past returns do not guarantee future results, and the stock with the higher historical return may already have its best growth priced in.

By beta (market sensitivity over 5 years), Aon plc (AON) is the lower-risk stock at 0.

10β versus Markel Corporation's 0. 44β — meaning MKL is approximately 355% more volatile than AON relative to the S&P 500. On balance sheet safety, Markel Corporation (MKL) carries a lower debt/equity ratio of 23% versus 173% for Aon plc — giving it more financial flexibility in a downturn.

By revenue growth (latest reported year), Aon plc (AON) is pulling ahead at 9.

4% versus -1. 0% for Markel Corporation (MKL). On earnings-per-share growth, the picture is similar: Aon plc grew EPS 36. 3% year-over-year, compared to -15. 1% for Markel Corporation. Over a 3-year CAGR, ERIE leads at 12. 7% annualised revenue growth. Higher growth typically commands a higher valuation multiple — check whether the premium P/E or P/S is justified by the growth rate using the PEG ratio.

Aon plc (AON) is the more profitable company, earning 21.

5% net margin versus 12. 7% for Markel Corporation — meaning it keeps 21. 5% of every revenue dollar as bottom-line profit. Operating margin tells a similar story: AON leads at 25. 3% versus 16. 5% for MKL. At the gross margin level — before operating expenses — MKL leads at 69. 4%, reflecting greater pricing power or product mix advantage. Stronger margins indicate durable pricing power, lower cost of revenue, or higher mix of software/services. They are one of the clearest signs of business quality.

The PEG ratio (forward P/E divided by expected earnings growth rate) is the most precise measure of undervaluation relative to growth potential.

By this metric, Markel Corporation (MKL) is the more undervalued stock at a PEG of 0. 64x versus Erie Indemnity Company's 1. 26x. A PEG below 1. 0 is traditionally considered the threshold for growth-adjusted undervaluation. On forward earnings alone, Markel Corporation (MKL) trades at 16. 0x forward P/E versus 17. 1x for Erie Indemnity Company — 1. 2x cheaper on a one-year earnings basis. Analyst consensus price targets imply the most upside for AON: 29. 0% to $404. 40.

All stocks in this comparison pay dividends.

Markel Corporation (MKL) offers the highest yield at 2. 7%, versus 0. 9% for Aon plc (AON).

For long-horizon retirement investors, Aon plc (AON) is the stronger choice — it scores higher on the combination of lower volatility, dividend reliability, and long-term compounding (low volatility (β 0.

10), 0. 9% yield, +219. 8% 10Y return). Both have compounded well over 10 years (AON: +219. 8%, MKL: +89. 3%), confirming both are viable long-term holds — but the lower-volatility option typically results in less emotional selling during corrections. Retirement portfolios generally favour predictability over maximum returns. Consult a financial advisor before making allocation decisions.

Both stocks operate in the Financial Services sector, making this a peer-level intra-sector comparison — the same macro tailwinds and headwinds will affect both.

In terms of investment character: MKL is a mid-cap deep-value stock; MMC is a mid-cap quality compounder stock; AON is a mid-cap quality compounder stock; ERIE is a mid-cap quality compounder stock. These fundamental differences mean investors should not choose between them on a single metric — the "better stock" depends entirely on which of these characteristics aligns with your investment strategy.