AJG vs WTW vs MMC vs AON

For growth investors, Arthur J.

Gallagher & Co. (AJG) is the stronger pick with 20. 7% revenue growth year-over-year, versus -2. 2% for Willis Towers Watson Public Limited Company (WTW). Willis Towers Watson Public Limited Company (WTW) offers the better valuation at 15. 9x trailing P/E (13. 2x forward), making it the more compelling value choice. Analysts rate Arthur J. Gallagher & Co. (AJG) a "Buy" — based on 29 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, Willis Towers Watson Public Limited Company (WTW) is the cheapest at 15.

9x versus Arthur J. Gallagher & Co. at 35. 1x. On forward P/E, Willis Towers Watson Public Limited Company is actually cheaper at 13. 2x. The PEG ratio (P/E divided by earnings growth rate) is the most growth-adjusted single valuation metric: Willis Towers Watson Public Limited Company wins at 0. 81x versus Arthur J. Gallagher & Co. 's 2. 35x — a PEG below 1. 0 traditionally signals the market is underpricing earnings growth.

Over the past 5 years, Arthur J.

Gallagher & Co. (AJG) delivered a total return of +41. 1%, compared to +1. 9% for Willis Towers Watson Public Limited Company (WTW). Over 10 years, the gap is even starker: AJG returned +372. 4% versus WTW's +132. 7%. 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), Arthur J.

Gallagher & Co. (AJG) is the lower-risk stock at 0. 09β versus Marsh & McLennan Companies, Inc. 's 0. 14β — meaning MMC is approximately 58% more volatile than AJG relative to the S&P 500. On balance sheet safety, Arthur J. Gallagher & Co. (AJG) carries a lower debt/equity ratio of 60% versus 173% for Aon plc — giving it more financial flexibility in a downturn.

By revenue growth (latest reported year), Arthur J.

Gallagher & Co. (AJG) is pulling ahead at 20. 7% versus -2. 2% for Willis Towers Watson Public Limited Company (WTW). On earnings-per-share growth, the picture is similar: Willis Towers Watson Public Limited Company grew EPS 1794% year-over-year, compared to -11. 9% for Arthur J. Gallagher & Co.. Over a 3-year CAGR, AJG leads at 17. 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 10. 7% for Arthur J. Gallagher & Co. — 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 18. 3% for AJG. At the gross margin level — before operating expenses — AJG leads at 54. 8%, 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, Willis Towers Watson Public Limited Company (WTW) is the more undervalued stock at a PEG of 0. 81x versus Arthur J. Gallagher & Co. 's 2. 35x. A PEG below 1. 0 is traditionally considered the threshold for growth-adjusted undervaluation. On forward earnings alone, Willis Towers Watson Public Limited Company (WTW) trades at 13. 2x forward P/E versus 16. 9x for Marsh & McLennan Companies, Inc. — 3. 7x cheaper on a one-year earnings basis. Analyst consensus price targets imply the most upside for AJG: 35. 9% to $274. 38.

All stocks in this comparison pay dividends.

Marsh & McLennan Companies, Inc. (MMC) offers the highest yield at 1. 8%, versus 0. 9% for Aon plc (AON).

For long-horizon retirement investors, Arthur J.

Gallagher & Co. (AJG) is the stronger choice — it scores higher on the combination of lower volatility, dividend reliability, and long-term compounding (low volatility (β 0. 09), 1. 3% yield, +372. 4% 10Y return). Both have compounded well over 10 years (AJG: +372. 4%, WTW: +132. 7%), 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: AJG is a mid-cap high-growth stock; WTW is a mid-cap deep-value stock; MMC is a mid-cap quality compounder stock; AON 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.