Three Houston companies ranked on Deloitte's annual list, with two cracking the top 100. Photo via Getty Images

Three Houston companies have made this year’s Deloitte North America Technology Fast 500 list.

The report ranks the fastest-growing technology, media, telecommunications, life sciences, fintech, and energy tech companies in North America. The Houston companies to make the list, along with their revenue growth rates from 2021-2024, include:

  • No. 16 Action1 Corp., a provider of cybersecurity software. Growth rate: 7,265 percent
  • No. 92 Cart.com, a commerce and logistics platform. Growth rate: 1,053 percent
  • No. 312 Tellihealth, a remote health care platform. Growth rate: 244 percent

“Houston’s unique blend of entrepreneurial energy and innovation continues to strengthen the local business community, and I’m thrilled to see Houston companies honored on the 2025 Deloitte Technology Fast 500 list. Congratulations to all the winners,” said Melinda Yee, managing partner in Deloitte’s Houston office.

Action1 is no stranger to lists like the Deloitte Technology Fast 500. For instance, the company ranked first among software companies and 29th overall on this year’s Inc. 5000, a list of the country’s fastest-growing private companies. Its growth rate from 2021 to 2024 reached 7,188 percent.

Mike Walters, president and co-founder of Action1, said in August that the Inc. 5000 achievement “reflects the dedication of Action1’s global team, who continue to execute against an ambitious vision: a world where cyberattacks exploiting vulnerabilities are entirely prevented across all types of devices, operating systems, and applications.”

Atlanta-based Impericus, operator of an AI-powered platform that connects health care providers with pharmaceutical and life sciences companies, topped the Deloitte list with a 2021-24 growth rate of 29,738 percent.

“Our mission is to set the standard for ethical AI-powered physician connections to pharma resources, accelerating and expanding patient access to needed treatments,” said Dr. Osama Hashmi, a dermatologist who’s co-founder and CEO of Impiricus. “As we continue to innovate quickly, we remain committed to building ethical bridges across this vital ecosystem.”

Inc. magazine has identified the fastest-growing companies in Houston. Nick Bee/Pexels

These are the 5 fastest-growing companies in Houston, according to a recent report

ready, set, grow

Bellaire-based startup Instafuel is pumping up its revenue in a big way.

Among the 250 fastest-growing companies in Texas identified by Inc. magazine, Instafuel tops the group of businesses based in the Houston metro area and ranks fifth statewide. Houston-based companies make up 68 of the state's fast-growing companies — eight Houston companies make up the top 25 list.

Instafuel, whose official corporate name is Fuel Husky LLC, provides mobile refueling services to B2B clients. The Inc. ranking, released March 13, shows Instafuel posted revenue growth of 1,353 percent from 2016 to 2018.

According to a November 2019 article published by CSP magazine, Instafuel has expanded to 30 trucks that have dispensed nearly 10 million gallons of fuel to more than 150 B2B clients in major Texas metro markets like Houston, Dallas-Fort Worth, and Austin. CSP covers the convenience and petroleum retailing industry.

"We've been bootstrapping … in stealth mode for the last four years, just trying to grow this business one [client] by one, trying to truly understand what it means to be a mobile refueler, or what we call a compact mobile refueler, and trying to target and understand the business model for small- to medium-sized business fleets," Nour Baki, vice president and co-founder of Instafuel, told the magazine.

Ranked second in the Houston area and sixth statewide by Inc. is Spring-based Bellatorum Resources LLC, whose revenue shot up 1,261 percent from 2016 to 2018. Bellatorum, a veteran-owned and veteran-operated investment company, specializes in mineral rights and oil royalty acquisitions.

"I think our work ethic and customer service is what makes us different from our competitors," Chris Bentley, president and CEO of Bellatorum Resources, told the Oil & Gas Council in July 2018.

"Based on the feedback I consistently receive from mineral owners, they tell me that many of our competitors fail to return phone calls and emails, and sometimes even fail to treat them with common courtesy and respect during their business dealings," Bentley added. "We believe in putting the mineral owner first, which always pays off for us."

At No. 3 in the Houston area and No. 8 statewide is Houston-based Sarvicus LLC. Sarvicus, an IT services and utilities provider, grew revenue by 1,048 percent from 2016 to 2018.

"Whether it's a process, piece of equipment, or a tool, we try to optimize its efficiency. When we are successful, that often translates to benefits for our customers," Sarvicus co-founder and CEO Marc Packard told CIOReview magazine.

Houston-based SIA Solutions LLC appears at No. 4 among Houston-area companies and No. 9 among Texas companies. From 2016 to 2018, revenue at the professional services engineering and consulting firm soared 1,030 percent.

"Because of our client-first philosophy, we're willing to take on tough challenges and deliver. It's in our culture. It's natural to us," CEO Srini Neralla told the McFerrin Center for Entrepreneurship at Texas A&M University's Mays Business School in November 2019. We put together strong teams comprising of firms our size or larger, including universities, in order to deliver what our clients want."

With a 2016-18 growth rate of 824 percent, Houston-based Zahroof Valves Inc. nails down the No. 5 spot among Houston-area companies and No. 14 among Texas companies. Zahroof Values makes and markets specialized valves for reciprocating gas compressors. Its investors include Saudi Aramco Energy Ventures LLC, the investment arm of oil giant Saudi Aramco.

In an August 2019 release, Zahroof Valves CEO Tony Gioffredi said: "Our commitment to driving positive change [in] the oil and gas industry is shown through our innovative products … ."

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Houston quantum energy chip startup emerges from stealth with $12M round

seed funding

Houston-based Casimir has emerged from stealth with a $12 million seed round to commercialize its quantum energy chip.

The round was led by Austin-based Scout Ventures. Lavrock Ventures, Cottonwood Technology, Capital Factory, American Deep Tech, and Tim Draper of Draper Associates also participated in the round. The oversubscribed round exceeded the company’s original $8 million target, according to a news release.

Casimir’s semiconductor chips can generate power from quantum vacuum fields without the need for batteries or charging. The company plans to commercialize its first-generation MicroSparc chip by 2028.

The MicroSparc chip measures 5 millimeters by 5 millimeters and is designed to produce 1.5 volts at 25 microamps, comparable to a small rechargeable battery, without degradation and no replacement cycle.

“Casimir represents exactly the kind of breakthrough dual-use technology Scout Ventures was built to back,” Brad Harrison, founder and managing partner at Scout Ventures, said in the release. “This is based on 100 years of science and we’re finally approaching a commercial product … We’re proud to lead this round and support Casimir’s journey from applied science to deployed technology.”

Casimir says it aims to scale its technology across the ”full power spectrum,” including large-scale energy systems that can power homes, commercial infrastructures and electric vehicles.

Casimir's scientific work has been supported by DARPA-funded nanofabrication research and its technology was incubated at the Limitless Space Institute (LSI). LSI is a nonprofit that works to innovate interstellar travel and was founded by Kam Ghaffarian. Technology investor and serial entrepreneur Ghaffarian has been behind companies like X-energy, Intuitive Machines, Axiom Space and Quantum Space.

Harold “Sonny” White, founder and CEO of Casimir, believes the technology can power devices for years without replacements.

“Millions of devices will operate for years without a battery ever needing to be replaced or recharged because we have engineered a customized Casimir cavity into hardware capable of producing persistent electrical power,” White added in the release. “I spent nearly two decades at NASA studying how we power humanity’s future. That work led me to the Casimir effect and the quantum vacuum, where new tools have allowed us to build on a century of scientific knowledge and bring abundant power to the world.”

Houston-based Fervo Energy bumps up IPO target to $1.82 billion

IPO update

Houston-based geothermal power company Fervo Energy is now eyeing an IPO that would raise $1.75 billion to $1.82 billion, up from the previous target of $1.33 billion.

In paperwork filed Monday, May 11 with the U.S. Securities and Exchange Commission, Fervo says it plans to sell 70 million shares of Class A common stock at $25 to $26 per share.

In addition, Fervo expects to grant underwriters 30-day options to buy up to 8.33 million additional shares of Class A common stock. This could raise nearly $200 million.

When it announced the IPO on May 4, Fervo aimed to sell 55.56 million shares at $21 to $24 per share, which would have raised $1.17 billion to $1.33 billion. The initial valuation target was $6.5 billion.

A date for the IPO hasn’t been scheduled. Fervo’s stock will be listed on Nasdaq under the ticker symbol FRVO.

Fervo, founded in 2017, has attracted about $1.5 billion in funding from investors such as Bill Gates-founded Breakthrough Energy Ventures, Google, Mitsubishi Heavy Industries, Devon Energy (which is moving its headquarters to Houston), Tesla co-founder JB Straubel, CalSTRS, Liberty Mutual Investments, AllianceBernstein, JPMorgan, Bank of America and Sumitomo Mitsui Trust Bank.

Fervo’s marquee project is Cape Station in Beaver County, Utah, the world’s largest EGS (enhanced geothermal system) project. The first phase will deliver 100 megawatts of baseload clean power, with the second phase adding another 400 megawatts. The site can accommodate 2 gigawatts of geothermal energy. Fervo holds more than 595,000 leased acres for potential expansion.

Cape Station has secured power purchase agreements for the entire 500-megawatt capacity. Customers include Houston-based Shell Energy North America and Southern California Edison.

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This article originally appeared on our sister site, EnergyCapitalHTX.com.