ASTI vs SPWR vs FSLR vs RUN

For growth investors, Sunrun Inc.

(RUN) is the stronger pick with 45. 1% revenue growth year-over-year, versus -100. 0% for Ascent Solar Technologies, Inc. Common Stock (ASTI). Sunrun Inc. (RUN) offers the better valuation at 8. 5x trailing P/E (15. 3x forward), making it the more compelling value choice. Analysts rate First Solar, Inc. (FSLR) a "Buy" — based on 73 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, Sunrun Inc.

(RUN) is the cheapest at 8. 5x versus First Solar, Inc. at 15. 5x. On forward P/E, SunPower Inc. is actually cheaper at 5. 5x — notably different from the trailing picture, reflecting expected earnings growth.

Over the past 5 years, First Solar, Inc.

(FSLR) delivered a total return of +204. 7%, compared to -100. 0% for Ascent Solar Technologies, Inc. Common Stock (ASTI). Over 10 years, the gap is even starker: FSLR returned +334. 7% versus ASTI's -100. 0%. 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), First Solar, Inc.

(FSLR) is the lower-risk stock at 1. 36β versus Ascent Solar Technologies, Inc. Common Stock's 4. 45β — meaning ASTI is approximately 226% more volatile than FSLR relative to the S&P 500. On balance sheet safety, First Solar, Inc. (FSLR) carries a lower debt/equity ratio of 5% versus 3% for Sunrun Inc. — giving it more financial flexibility in a downturn.

By revenue growth (latest reported year), Sunrun Inc.

(RUN) is pulling ahead at 45. 1% versus -100. 0% for Ascent Solar Technologies, Inc. Common Stock (ASTI). On earnings-per-share growth, the picture is similar: Sunrun Inc. grew EPS 113. 3% year-over-year, compared to 0. 0% for SunPower Inc.. Over a 3-year CAGR, SPWR leads at 65. 3% 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.

First Solar, Inc.

(FSLR) is the more profitable company, earning 29. 3% net margin versus -10. 5% for SunPower Inc. — meaning it keeps 29. 3% of every revenue dollar as bottom-line profit. Operating margin tells a similar story: FSLR leads at 32. 3% versus -4. 3% for RUN. At the gross margin level — before operating expenses — SPWR leads at 48. 5%, 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, SunPower Inc.

(SPWR) trades at 5. 5x forward P/E versus 15. 3x for Sunrun Inc. — 9. 8x cheaper on a one-year earnings basis. Analyst consensus price targets imply the most upside for SPWR: 1350. 5% to $15. 81.

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, First Solar, Inc.

(FSLR) is the stronger choice — it scores higher on the combination of lower volatility, dividend reliability, and long-term compounding (+334. 7% 10Y return). Ascent Solar Technologies, Inc. Common Stock (ASTI) carries a higher beta of 4. 45 — meaning larger drawdowns in market downturns, which matters significantly when you cannot wait years for a recovery. Both have compounded well over 10 years (FSLR: +334. 7%, ASTI: -100. 0%), 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 Energy sector, making this a peer-level intra-sector comparison — the same macro tailwinds and headwinds will affect both.

In terms of investment character: ASTI is a small-cap quality compounder stock; SPWR is a small-cap quality compounder stock; FSLR is a mid-cap high-growth stock; RUN is a small-cap high-growth 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.