Alto Ingredients, Inc. ALTO and Aemetis, Inc. AMTX operate in the renewable fuels and low-carbon energy industry, a sector benefiting from growing demand for cleaner transportation fuels and sustainable industrial solutions. Both companies are positioned within the broader bioenergy market, where government policies, decarbonization goals and evolving energy needs continue to shape competitive dynamics and long-term growth opportunities.
While Alto Ingredients has expanded beyond conventional ethanol production into specialty alcohols and essential ingredients for food, beverage and industrial markets, Aemetis has built a broader renewable energy platform that includes ethanol, biodiesel, renewable natural gas and sustainable aviation fuel projects. Their contrasting strategic priorities and operating models make them an interesting comparison for investors seeking to evaluate their competitive strengths, execution capabilities and prospects for long-term value creation.
Let's discuss in detail.
The Case for Alto Ingredients Stock
Alto Ingredients operates as a diversified producer of renewable fuels, specialty alcohols and essential ingredients, serving customers across the health, beauty, food, beverage, industrial and agricultural markets. Its diversified portfolio and focus on higher-value products have contributed to a notable improvement in operating performance. In the first quarter of 2026, the company reported earnings of 5 cents per share, against a loss of 16 cents in the year-ago quarter. Adjusted EBITDA improved to $4.7 million from negative $4.4 million, while gross profit swung to $9.2 million from a gross loss of $1.8 million, reflecting improved operating conditions, the company's strategic realignment and unrealized derivative gains.
Favorable industry conditions also supported performance during the quarter. Strong export demand, higher export premiums relative to domestic renewable fuel sales and improving corn oil prices boosted margins. Board corn crush margins increased to 17 cents per gallon from just 2 cents a year earlier, while essential ingredients returns improved to 53.4% from 48.2%. The company also expects demand support from export markets and the potential expansion of year-round E15 adoption.
Alto Ingredients continues to invest in initiatives aimed at enhancing long-term profitability. A debottlenecking project at the Pekin dry mill is expected to increase annual production capacity by about 5 million gallons, while additional CO2 infrastructure investments are designed to improve operational flexibility and support higher-value opportunities. The company is also evaluating carbon capture and sequestration initiatives and expanding its participation in Section 45Z tax credits, having recognized $3.9 million in tax-credit earnings during the first quarter and expecting roughly $15 million in annual net proceeds from qualifying production volumes.
However, Alto Ingredients remains exposed to the risk of weaker industry margins if production outpaces demand. Management acknowledged that strong spring crush margins have historically encouraged higher ethanol production, often leading to oversupply and margin compression in the second half of the year. While export demand and the potential expansion of year-round E15 could help absorb additional volumes, their impact remains uncertain.
The Case for Aemetis Stock
Aemetis has built a diversified renewable fuels platform spanning California ethanol, Dairy Renewable Natural Gas (“RNG”) and India biodiesel operations. Its multi-segment business model contributed to a notable improvement in financial performance during the first quarter of 2026. Revenues increased 27% year over year to $54.6 million, while gross profit improved to $2.8 million from a gross loss of $5.1 million. Operating loss narrowed by approximately 60%, reflecting stronger execution across all three operating segments and the contribution from Section 45Z production tax credits.
The company's growth strategy is centered on expanding production capacity while increasing the value of its low-carbon fuel portfolio. In the quarter, Dairy RNG sales volumes climbed 55% year over year to 110,000 MMBtu, supported by seven approved Low Carbon Fuel Standard (“LCFS”) pathways with an average carbon intensity score of negative 380. Aemetis is also expanding its dairy digester network, which is expected to support higher renewable natural gas production and additional LCFS credit generation.
The company continues to invest in projects aimed at strengthening long-term earnings and improving its competitive position in low-carbon fuels. Construction is progressing on the mechanical vapor recompression project at the Keyes ethanol plant, which is expected to reduce fossil natural gas consumption by about 80% while enhancing cash flow through lower operating costs and additional tax-credit opportunities. The company is also advancing its India biodiesel business, planned IPO and sustainable aviation fuel project to diversify growth opportunities.
However, Aemetis continues to face execution and financing risks as it advances several large-scale growth projects. In addition, the pace of project development and expected returns remain dependent on regulatory approvals, financing availability and the continued evolution of low-carbon fuel incentive programs.
Valuation & Price Performance of ALTO & AMTX
Alto Ingredients currently trades at a forward price-to-sales (P/S) ratio of 0.34, slightly above Aemetis' forward P/S ratio of 0.32.
P/S Ratio (Forward 12 Months)
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Over the past year, Alto Ingredients has significantly outperformed Aemetis. ALTO gained 287.9%, while AMTX declined 52.3%.
One Year Price Performance
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ALTO vs. AMTX: Which Stock Comes Out Ahead?
Both Alto Ingredients and Aemetis are expanding beyond conventional ethanol production to capitalize on opportunities in the low-carbon fuels market. However, Alto Ingredients currently presents the stronger investment case, supported by its return to profitability, improving margins, growing specialty alcohol and ingredients business, and expected benefits from Section 45Z tax credits and ongoing capacity expansion initiatives.
While Aemetis offers significant long-term potential through the Dairy RNG, sustainable aviation fuel and India biodiesel initiatives, much of its growth depends on successful project execution and financing. With stronger operating momentum, lower execution risk and a clearer path to near-term earnings growth, ALTO emerges as the more compelling investment opportunity.
Both ALTO and AMTX carry a Zacks Rank #3 (Hold) at present. You can see the complete list of today’s Zacks #1 Rank (Strong buy) stocks here.
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This article originally published on Zacks Investment Research (zacks.com).