Compare ACI Worldwide, Inc. (ACIW) vs Microsoft Corporation (MSFT) Stock

ACI Worldwide, Inc. (ACIW) offers the better valuation at 18.4x trailing P/E (15.7x 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, ACI Worldwide, Inc. (ACIW) is the cheapest at 18.4x versus Microsoft Corporation at 28.8x. On forward P/E, ACI Worldwide, Inc. is actually cheaper at 15.7x. The PEG ratio (P/E divided by earnings growth rate) is the most growth-adjusted single valuation metric: ACI Worldwide, Inc. wins at 0.55x versus Microsoft Corporation's 1.27x — a PEG below 1.0 traditionally signals the market is underpricing earnings growth.

Over the past 5 years, Microsoft Corporation (MSFT) delivered a total return of +71.9%, compared to +0.8% for ACI Worldwide, Inc. (ACIW). A $10,000 investment in MSFT five years ago would be worth approximately $17K today (assuming dividends reinvested). Over 10 years, the gap is even starker: MSFT returned +718.2% versus ACIW's +112.6%. 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), Microsoft Corporation (MSFT) is the lower-risk stock at 0.88β versus ACI Worldwide, Inc.'s 1.11β — meaning ACIW is approximately 25% more volatile than MSFT relative to the S&P 500. On balance sheet safety, Microsoft Corporation (MSFT) carries a lower debt/equity ratio of 18% versus 55% for ACI Worldwide, Inc. — giving it more financial flexibility in a downturn.

Microsoft Corporation (MSFT) is the more profitable company, earning 36.1% net margin versus 12.9% for ACI Worldwide, Inc. — meaning it keeps 36.1% of every revenue dollar as bottom-line profit. Operating margin tells a similar story: MSFT leads at 45.6% versus 18.7% for ACIW. At the gross margin level — before operating expenses — MSFT leads at 68.8%, 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, ACI Worldwide, Inc. (ACIW) is the more undervalued stock at a PEG of 0.55x versus Microsoft Corporation's 1.27x. A PEG below 1.0 is traditionally considered the threshold for growth-adjusted undervaluation. On forward earnings alone, ACI Worldwide, Inc. (ACIW) trades at 15.7x forward P/E versus 23.8x for Microsoft Corporation — 8.1x cheaper on a one-year earnings basis. Analyst consensus price targets imply the most upside for ACIW: 76.4% to $70.00.

In this comparison, MSFT (0.8% yield) pays a dividend. ACIW does not pay a meaningful dividend and should not be held primarily for income.

For long-horizon retirement investors, Microsoft Corporation (MSFT) is the stronger choice — it scores higher on the combination of lower volatility, dividend reliability, and long-term compounding (low volatility (β 0.88), 0.8% yield, +718.2% 10Y return). Both have compounded well over 10 years (MSFT: +718.2%, ACIW: +112.6%), 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. MSFT pays a dividend while ACIW does 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.