DIOD vs AOSL vs POWI vs MPWR

For growth investors, Monolithic Power Systems, Inc.

(MPWR) is the stronger pick with 26. 4% revenue growth year-over-year, versus 5. 9% for Power Integrations, Inc. (POWI). Diodes Incorporated (DIOD) offers the better valuation at 78. 7x trailing P/E (48. 5x forward), making it the more compelling value choice. Analysts rate Diodes Incorporated (DIOD) a "Buy" — based on 13 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, Diodes Incorporated (DIOD) is the cheapest at 78.

7x versus Power Integrations, Inc. at 184. 2x. On forward P/E, Diodes Incorporated is actually cheaper at 48. 5x.

Over the past 5 years, Monolithic Power Systems, Inc.

(MPWR) delivered a total return of +366. 2%, compared to -8. 3% for Power Integrations, Inc. (POWI). Over 10 years, the gap is even starker: MPWR returned +24. 9% versus AOSL's +172. 1%. 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), Power Integrations, Inc.

(POWI) is the lower-risk stock at 2. 08β versus Alpha and Omega Semiconductor Limited's 2. 81β — meaning AOSL is approximately 35% more volatile than POWI relative to the S&P 500. On balance sheet safety, Monolithic Power Systems, Inc. (MPWR) carries a lower debt/equity ratio of 1% versus 6% for Alpha and Omega Semiconductor Limited — giving it more financial flexibility in a downturn.

By revenue growth (latest reported year), Monolithic Power Systems, Inc.

(MPWR) is pulling ahead at 26. 4% versus 5. 9% for Power Integrations, Inc. (POWI). On earnings-per-share growth, the picture is similar: Diodes Incorporated grew EPS 50. 5% year-over-year, compared to -746. 2% for Alpha and Omega Semiconductor Limited. Over a 3-year CAGR, MPWR leads at 15. 9% 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.

Monolithic Power Systems, Inc.

(MPWR) is the more profitable company, earning 22. 1% net margin versus -13. 9% for Alpha and Omega Semiconductor Limited — meaning it keeps 22. 1% of every revenue dollar as bottom-line profit. Operating margin tells a similar story: MPWR leads at 26. 1% versus -4. 1% for AOSL. At the gross margin level — before operating expenses — MPWR leads at 55. 2%, 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.

On forward earnings alone, Diodes Incorporated (DIOD) trades at 48.

5x forward P/E versus 73. 1x for Monolithic Power Systems, Inc. — 24. 6x cheaper on a one-year earnings basis. Analyst consensus price targets imply the most upside for POWI: 10. 0% to $79. 00.

In this comparison, POWI (1.

2% yield), MPWR (0. 4% yield) pay a dividend. DIOD, AOSL do not pay a meaningful dividend and should not be held primarily for income.

For long-horizon retirement investors, Power Integrations, Inc.

(POWI) is the stronger choice — it scores higher on the combination of lower volatility, dividend reliability, and long-term compounding (1. 2% yield, +232. 7% 10Y return). Monolithic Power Systems, Inc. (MPWR) carries a higher beta of 2. 28 — meaning larger drawdowns in market downturns, which matters significantly when you cannot wait years for a recovery. Both have compounded well over 10 years (POWI: +232. 7%, MPWR: +24. 9%), 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: DIOD is a small-cap quality compounder stock; AOSL is a small-cap quality compounder stock; POWI is a small-cap quality compounder stock; MPWR is a mid-cap high-growth stock. POWI pays a dividend while DIOD, AOSL, MPWR 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.