IPWR vs POWI vs AEIS vs VICR vs MPWR

For growth investors, Monolithic Power Systems, Inc.

(MPWR) is the stronger pick with 26. 4% revenue growth year-over-year, versus -56. 1% for Ideal Power Inc. (IPWR). Advanced Energy Industries, Inc. (AEIS) offers the better valuation at 91. 7x trailing P/E (40. 4x forward), making it the more compelling value choice. Analysts rate Power Integrations, Inc. (POWI) a "Buy" — based on 16 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, Advanced Energy Industries, Inc.

(AEIS) is the cheapest at 91. 7x versus Power Integrations, Inc. at 184. 2x. On forward P/E, Advanced Energy Industries, Inc. is actually cheaper at 40. 4x. The PEG ratio (P/E divided by earnings growth rate) is the most growth-adjusted single valuation metric: Vicor Corporation wins at 2. 10x versus Advanced Energy Industries, Inc. 's 21. 57x.

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

(MPWR) delivered a total return of +366. 2%, compared to -43. 0% for Ideal Power Inc. (IPWR). Over 10 years, the gap is even starker: VICR returned +27. 0% versus IPWR's -90. 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), Power Integrations, Inc.

(POWI) is the lower-risk stock at 2. 08β versus Vicor Corporation's 2. 79β — meaning VICR is approximately 34% 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 50% for Advanced Energy Industries, Inc. — 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 -56. 1% for Ideal Power Inc. (IPWR). On earnings-per-share growth, the picture is similar: Vicor Corporation grew EPS 1764% 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.

Vicor Corporation (VICR) is the more profitable company, earning 29.

1% net margin versus -280. 4% for Ideal Power Inc. — meaning it keeps 29. 1% of every revenue dollar as bottom-line profit. Operating margin tells a similar story: MPWR leads at 26. 1% versus -289. 8% for IPWR. 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, Vicor Corporation (VICR) is the more undervalued stock at a PEG of 2. 10x versus Advanced Energy Industries, Inc. 's 21. 57x. Both stocks trade at elevated growth-adjusted valuations, so expected growth needs to materialise. On forward earnings alone, Advanced Energy Industries, Inc. (AEIS) trades at 40. 4x forward P/E versus 94. 3x for Vicor Corporation — 53. 9x 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), AEIS (0. 1% yield) pay a dividend. IPWR, VICR 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). Ideal Power Inc. (IPWR) carries a higher beta of 2. 41 — 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%, IPWR: -90. 3%), 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.

These companies operate in different sectors (IPWR (Industrials) and POWI (Technology) and AEIS (Industrials) and VICR (Technology) and MPWR (Technology)), which means they face different economic cycles, regulatory environments, and macro sensitivities — making direct comparison nuanced.

In terms of investment character: IPWR is a small-cap quality compounder stock; POWI is a small-cap quality compounder stock; AEIS is a mid-cap high-growth stock; VICR is a mid-cap quality compounder stock; MPWR is a mid-cap high-growth stock. POWI pays a dividend while IPWR, AEIS, VICR, 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.