MRX vs IBKR vs MKTX vs LPLA

For growth investors, LPL Financial Holdings Inc.

(LPLA) is the stronger pick with 37. 2% revenue growth year-over-year, versus 3. 8% for MarketAxess Holdings Inc. (MKTX). Marex Group plc Ordinary Shares (MRX) offers the better valuation at 13. 4x trailing P/E (10. 6x forward), making it the more compelling value choice. Analysts rate Marex Group plc Ordinary Shares (MRX) a "Buy" — based on 6 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, Marex Group plc Ordinary Shares (MRX) is the cheapest at 13.

4x versus Interactive Brokers Group, Inc. at 37. 7x. On forward P/E, Marex Group plc Ordinary Shares is actually cheaper at 10. 6x. The PEG ratio (P/E divided by earnings growth rate) is the most growth-adjusted single valuation metric: Marex Group plc Ordinary Shares wins at 0. 27x versus MarketAxess Holdings Inc. 's 3. 03x — a PEG below 1. 0 traditionally signals the market is underpricing earnings growth.

Over the past 5 years, Interactive Brokers Group, Inc.

(IBKR) delivered a total return of +386. 1%, compared to -61. 8% for MarketAxess Holdings Inc. (MKTX). Over 10 years, the gap is even starker: LPLA returned +1241% versus MKTX's +38. 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), MarketAxess Holdings Inc.

(MKTX) is the lower-risk stock at -0. 28β versus Interactive Brokers Group, Inc. 's 1. 93β — meaning IBKR is approximately -787% more volatile than MKTX relative to the S&P 500. On balance sheet safety, Interactive Brokers Group, Inc. (IBKR) carries a lower debt/equity ratio of 0% versus 8% for Marex Group plc Ordinary Shares — giving it more financial flexibility in a downturn.

By revenue growth (latest reported year), LPL Financial Holdings Inc.

(LPLA) is pulling ahead at 37. 2% versus 3. 8% for MarketAxess Holdings Inc. (MKTX). On earnings-per-share growth, the picture is similar: Marex Group plc Ordinary Shares grew EPS 42. 3% year-over-year, compared to -22. 2% for LPL Financial Holdings Inc.. 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.

MarketAxess Holdings Inc.

(MKTX) is the more profitable company, earning 29. 0% net margin versus 5. 1% for LPL Financial Holdings Inc. — meaning it keeps 29. 0% of every revenue dollar as bottom-line profit. Operating margin tells a similar story: IBKR leads at 86. 0% versus 13. 4% for LPLA. At the gross margin level — before operating expenses — IBKR leads at 89. 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, Marex Group plc Ordinary Shares (MRX) is the more undervalued stock at a PEG of 0. 27x versus MarketAxess Holdings Inc. 's 3. 03x. A PEG below 1. 0 is traditionally considered the threshold for growth-adjusted undervaluation. On forward earnings alone, Marex Group plc Ordinary Shares (MRX) trades at 10. 6x forward P/E versus 33. 6x for Interactive Brokers Group, Inc. — 23. 0x cheaper on a one-year earnings basis. Analyst consensus price targets imply the most upside for LPLA: 42. 4% to $441. 00.

All stocks in this comparison pay dividends.

MarketAxess Holdings Inc. (MKTX) offers the highest yield at 2. 0%, versus 0. 4% for Interactive Brokers Group, Inc. (IBKR).

For long-horizon retirement investors, MarketAxess Holdings Inc.

(MKTX) is the stronger choice — it scores higher on the combination of lower volatility, dividend reliability, and long-term compounding (low volatility (β -0. 28), 2. 0% yield). Interactive Brokers Group, Inc. (IBKR) carries a higher beta of 1. 93 — meaning larger drawdowns in market downturns, which matters significantly when you cannot wait years for a recovery. Both have compounded well over 10 years (MKTX: +38. 3%, IBKR: +823. 8%), 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: MRX is a small-cap high-growth stock; IBKR is a mid-cap quality compounder stock; MKTX is a small-cap quality compounder stock; LPLA is a mid-cap high-growth stock. MRX, MKTX pay a dividend while IBKR, LPLA do not, making them suitable for different income and tax situations. 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.