DIOD vs SIMO vs MPWR vs POWI

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). Silicon Motion Technology Corporation (SIMO) offers the better valuation at 16. 6x trailing P/E (29. 9x 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, Silicon Motion Technology Corporation (SIMO) is the cheapest at 16.

6x versus Power Integrations, Inc. at 184. 2x. On forward P/E, Silicon Motion Technology Corporation is actually cheaper at 29. 9x. The PEG ratio (P/E divided by earnings growth rate) is the most growth-adjusted single valuation metric: Silicon Motion Technology Corporation wins at 0. 66x versus Monolithic Power Systems, Inc. 's 2. 48x — a PEG below 1. 0 traditionally signals the market is underpricing earnings growth.

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 POWI's +232. 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), Silicon Motion Technology Corporation (SIMO) is the lower-risk stock at 1.

90β versus Monolithic Power Systems, Inc. 's 2. 28β — meaning MPWR is approximately 20% more volatile than SIMO relative to the S&P 500. On balance sheet safety, Monolithic Power Systems, Inc. (MPWR) carries a lower debt/equity ratio of 1% versus 5% for Diodes Incorporated — 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 -65. 2% for Monolithic Power Systems, Inc.. 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 4. 5% for Diodes Incorporated — 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 2. 4% for DIOD. 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.

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, Silicon Motion Technology Corporation (SIMO) is the more undervalued stock at a PEG of 0. 66x versus Monolithic Power Systems, Inc. 's 2. 48x. A PEG below 1. 0 is traditionally considered the threshold for growth-adjusted undervaluation. On forward earnings alone, Silicon Motion Technology Corporation (SIMO) trades at 29. 9x forward P/E versus 73. 1x for Monolithic Power Systems, Inc. — 43. 3x 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, SIMO (3.

3% yield), POWI (1. 2% yield), MPWR (0. 4% yield) pay a dividend. DIOD does not pay a meaningful dividend and should not be held primarily for income.

For long-horizon retirement investors, Silicon Motion Technology Corporation (SIMO) is the stronger choice — it scores higher on the combination of lower volatility, dividend reliability, and long-term compounding (3.

3% yield, +533. 8% 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 (SIMO: +533. 8%, 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; SIMO is a small-cap deep-value stock; MPWR is a mid-cap high-growth stock; POWI is a small-cap quality compounder stock. SIMO, POWI pay a dividend while DIOD, 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.