ACIW vs FISV

For growth investors, ACI Worldwide, Inc.

(ACIW) is the stronger pick with 10. 4% revenue growth year-over-year, versus 3. 6% for Fiserv, Inc. (FISV). Fiserv, Inc. (FISV) offers the better valuation at 9. 0x trailing P/E (7. 0x forward), making it the more compelling value choice. Analysts rate ACI Worldwide, Inc. (ACIW) a "Buy" — based on 17 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, Fiserv, Inc.

(FISV) is the cheapest at 9. 0x versus ACI Worldwide, Inc. at 21. 6x. On forward P/E, Fiserv, Inc. is actually cheaper at 7. 0x. The PEG ratio (P/E divided by earnings growth rate) is the most growth-adjusted single valuation metric: Fiserv, Inc. wins at 0. 20x versus ACI Worldwide, Inc. 's 0. 67x — a PEG below 1. 0 traditionally signals the market is underpricing earnings growth.

Over the past 5 years, ACI Worldwide, Inc.

(ACIW) delivered a total return of +21. 7%, compared to -51. 7% for Fiserv, Inc. (FISV). Over 10 years, the gap is even starker: ACIW returned +131. 7% versus FISV's +9. 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), Fiserv, Inc.

(FISV) is the lower-risk stock at 0. 94β versus ACI Worldwide, Inc. 's 1. 03β — meaning ACIW is approximately 9% more volatile than FISV relative to the S&P 500. On balance sheet safety, ACI Worldwide, Inc. (ACIW) carries a lower debt/equity ratio of 57% versus 113% for Fiserv, Inc. — giving it more financial flexibility in a downturn.

By revenue growth (latest reported year), ACI Worldwide, Inc.

(ACIW) is pulling ahead at 10. 4% versus 3. 6% for Fiserv, Inc. (FISV). On earnings-per-share growth, the picture is similar: Fiserv, Inc. grew EPS 17. 8% year-over-year, compared to 13. 1% for ACI Worldwide, Inc.. Over a 3-year CAGR, ACIW leads at 7. 4% 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.

Fiserv, Inc.

(FISV) is the more profitable company, earning 16. 4% net margin versus 12. 9% for ACI Worldwide, Inc. — meaning it keeps 16. 4% of every revenue dollar as bottom-line profit. Operating margin tells a similar story: FISV leads at 26. 9% versus 18. 7% for ACIW. At the gross margin level — before operating expenses — FISV leads at 59. 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, Fiserv, Inc. (FISV) is the more undervalued stock at a PEG of 0. 20x versus ACI Worldwide, Inc. 's 0. 67x. A PEG below 1. 0 is traditionally considered the threshold for growth-adjusted undervaluation. On forward earnings alone, Fiserv, Inc. (FISV) trades at 7. 0x forward P/E versus 19. 0x for ACI Worldwide, Inc. — 12. 0x cheaper on a one-year earnings basis. Analyst consensus price targets imply the most upside for ACIW: 50. 1% to $70. 00.

None of the stocks in this comparison currently pay a material dividend.

All are effectively zero-yield and should be held for capital appreciation rather than income.

For long-horizon retirement investors, ACI Worldwide, Inc.

(ACIW) is the stronger choice — it scores higher on the combination of lower volatility, dividend reliability, and long-term compounding (low volatility (β 1. 03), +131. 7% 10Y return). Both have compounded well over 10 years (ACIW: +131. 7%, FISV: +9. 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 Technology sector, making this a peer-level intra-sector comparison — the same macro tailwinds and headwinds will affect both.

In terms of investment character: ACIW is a small-cap quality compounder stock; FISV is a mid-cap deep-value 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.