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.”

These are the four fastest-growing tech companies in Houston, according to Deloitte. Photo by Shobeir Ansar/Getty Images

4 fast-growing Houston tech companies secure spots on Deloitte list

big wins

Deloitte’s annual North America Technology Fast 500 list includes four Houston companies this year — all boasting of significant growth.

For Houston, Direct Digital Holdings, Inc. took the highest-ranking spot at No. 101 (up from 108 previous year) with 1,184 percent growth. NatGas Hub LLC (No. 286, 407 percent growth), Liongard (No. 437, 246 percent growth), and Stratus Medical LLC (No. 483, 212 percent growth) also made the list, which is an annual ranking of the fastest-growing North American companies in technology, energy tech sectors, telecommunications, life sciences, media, and fintech.

"Houston continues to demonstrate its prowess in fostering growth and technological advancement and I’m incredibly proud to see some of our local companies making significant strides and earning their well-deserved spots on the 2024 Deloitte Technology Fast 500 list,” Houston managing partner at Deloitte Melinda Yee says in a news release.

Award winners were selected based on fiscal year revenue growth from 2019 to 2022.

The companies achieved revenue growth ranging from 201 percent to 153,625 percent over the three-year time frame with an average growth rate of 1,981 percent and a median growth rate of 460 percent, according to a news release. Texas accounts for 6 percent of the winning companies with 73 percent of the companies from Texas are in the software sector.

“These companies exemplify the entrepreneurial spirit and innovative mindset that define Houston's dynamic business ecosystem,” Yee adds.

In 2023, the Houston representation looked similar. Direct Digital Holdings again topped the Houston rankings at No. 108, with Liongard, NatGasHub.com, and P97 Networks also showing substantial growth. As a state, Texas had 30 companies that made the list of the 541 ranked. In 2022, just one Houston company was recognized, as at No. 372 Onit reported revenue increase of 369 percent.

Biopharmaceutical company TG Therapeutics, Inc. was the No.1 spot in 2024 with a growth rate of 153,625 percent from 2020 to 2023. See the full list here.
Amy Chronis is passing over the local leadership reins at Deloitte to Melinda Yee. Photos courtesy

Prominent Houston energy business leader to retire, successor named

in transition

Amy Chronis, a Houston business leader within the energy industry and beyond, is retiring next summer. Her replacement has been named.

Melinda Yee will be the incoming Houston managing partner at Deloitte, replacing Chronis who held the role along with the title vice chair and US energy and chemicals leader. Chronis will retire in June 2024, and Yee's new role is effective January 2.

“Melinda has been an active and valued member of Deloitte’s Houston leadership team. She brings an impressive depth of both industry and marketplace knowledge to her new role as managing partner,” Chronis says in a news release. “I am confident that she will be a great leader for our Houston professionals and in the local community.”

Yee has worked at Deloitte for over 30 years and has served as both Deloitte’s central region risk and advisory leader as well as the Houston risk and advisory leader. She also held the title of energy and chemicals leader within Deloitte’s mergers, acquisitions, and restructuring services practice. She's worked on transactions across the energy value chain, as well as waste management, manufacturing, industrials, services, retail operations and investment management, per the release.

“I am honored to have been asked to serve as the managing partner for Deloitte’s Houston practice,” Yee says in the release. “I look forward to continuing the great work Deloitte has accomplished under Amy’s leadership, delivering results for our clients and making an impact in the Houston community.”

In addition to her role at Deloitte, she serves as a board member for Junior Achievement of Southeast Texas, a member of the Energy Transition Committee for the Greater Houston Partnership, and is Audit Committee chair, director and trustee at the University of Colorado Foundation.

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This article originally ran on EnergyCapital.

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Rice scientist earns $600K NSF award to study distractions in digital age

fresh funding

Rice University psychologist Kirsten Adam has received a $600,000 National Science Foundation CAREER Award to research how visual distractions like phone notifications, flashing alerts, crowded screens and busy workspaces can negatively impact focus—and how the brain works to try to regain it.

The highly competitive five-year NSF grants are given to career faculty members with the potential to serve as academic models and leaders in research and education. Adam’s work will aim to clarify how the brain refocuses in the age of screens, instant gratification and other lingering distractions. The funding will also be used to train graduate students in advanced cognitive neuroscience methods, expand access to electroencephalography (EEG) and for public data sharing.

“Kirsten is a valued member of the School of Social Sciences, and we are thrilled that she has been awarded the prestigious NSF CAREER,” Rachel Kimbro, dean of social sciences, said in a news release. “Because distractions continue to increase all around us, her research is timely and imperative to understanding their widespread impacts on the human brain.”

In Adam’s lab, participants complete simplified visual search tasks while their brain activity is recorded using EEG, allowing researchers to measure attention shifts in real time. This process then captures the moment attention is drawn from a goal and how much effort it takes to refocus.

According to Rice, Adam’s work will test long-standing theories about distraction. The research is meant to have real-world implications for jobs and aspects of everyday life where attention to detail is key, including medical imaging, airport security screening and even driving.

“At any given moment, there’s far more information in the world than our brains can process,” Adam added in the release. “Attention is what determines what reaches our awareness and what doesn’t.”

Additionally, the research could inform the design of new technologies that would support focus and decision-making, according to Rice.

“We’re not trying to make attention limitless,” Adam added. “We’re trying to understand how it actually works, so we can stop designing environments and expectations that fight against it.”

12 Houston climatetech startups join Greentown Labs' growing incubator

Startup Talk

More than 40 climatetech startups joined the Greentown Labs Houston community in the second half of 2025, 12 of which hail from the Bayou City.

The companies are among a group of nearly 70 total that joined the climatetech incubator, which is co-located in Houston and Boston, in Q3 and Q4.

The new companies that have joined the Houston incubator specialize in a variety of clean energy applications, from green hydrogen-producing water-splitting cycles to drones that service wind turbines.

The local startups that joined Greentown Houston include:

  • Houston-based Wise Energie, which delivers turnkey microgrids that blend vertical-axis wind, solar PV, and battery storage into a single, silent system.
  • The Woodlands-based Resollant, which is developing compact, zero-emissions hydrogen and carbon reactors to provide low-cost, scalable clean hydrogen and high-purity carbon for the energy and manufacturing sectors.
  • Houston-based ClarityCastle, which designs and manufactures modular, soundproof work pods that replace traditional drywall construction with reusable, low-waste alternatives made from recycled materials.
  • Houston-based WattSto Energy, which manufactures vanadium redox flow batteries to deliver long-duration storage for both grid-scale projects and off-grid microgrids.
  • Houston-based AMPeers, which delivers advanced, high-temperature superconductors in the U.S. at a fraction of traditional costs.
  • Houston-based Biosimo, which is developing bio-based platform chemicals, pioneering sustainable chemistry for a healthier planet and economy.
  • Houston-based Ententia, which offers purpose-built, generative AI for industry.
  • Houston-based GeoKiln Energy Innovation, which is developing a new way to produce clean hydrogen by accelerating natural geologic reactions in iron-rich rock formations using precision electrical heating.
  • Houston-based Timbergrove, which builds AI and IoT solutions that connect and optimize assets—boosting visibility, safety, and efficiency.
  • Houston-based dataVediK, which combines energy-domain expertise with advanced machine learning and intelligent automation to empower organizations to achieve operational excellence and accelerate their sustainability goals.
  • Houston-based Resonant Thermal Systems, which uses a resonant energy-transfer (RET) system to extract critical minerals from industrial and natural brines without using membranes or grid electricity.
  • Houston-based Torres Orbital Mining (TOM),which develops autonomous excavation systems for extreme environments on Earth and the moon, enabling safe, data-driven resource recovery and laying the groundwork for sustainable off-world industry.

Other startups from around the world joined the Houston incubator in the same time period, including:

More than 100 startups joined Greentown this year, according to an end-of-year reflection shared by Greentown CEO Georgina Campbell Flatter.

Flatter joined Greentown in the top leadership role in February 2025. She succeeded former CEO and president Kevin Knobloch, who stepped down in July 2024.

"I moved back to the United States in March 2025 after six years overseas—2,000 miles, three children, and one very patient husband later. Over these months, I’ve had the chance to hear from the entrepreneurs, industry leaders, investors, and partners who make this community thrive. What I’ve experienced has left me brimming with urgent optimism for the future we’re building together," she said in the release.

According to Flatter, Greentown alumni raised more than $2 billion this year and created more than 3,000 jobs.

"Greentown startups and ecosystem leaders—from Boston, Houston, and beyond—are showing that we can move further and faster together. That we don’t have to choose between more energy or lower emissions, or between increasing sustainability and boosting profit. I call this the power of 'and,'" Flatter added. "We’re working for energy and climate, innovation and scale, legacy industry and startups, prosperity for people and planet. The 'and' is where possibility expands."

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This article originally appeared on EnergyCaptialHTX.com.

Intuitive Machines forms partnership with Italian companies for lunar exploration services

to the moon

Houston-based space technology, infrastructure and services company Intuitive Machines has forged a partnership with two Italian companies to offer infrastructure, communication and navigation services for exploration of the moon.

Intuitive Machines’ agreement with the two companies, Leonardo and Telespazio, paves the way for collaboration on satellite services for NASA, a customer of Intuitive Machines, and the European Space Agency, a customer of Leonardo and Telespazio. Leonardo, an aerospace, defense and security company, is the majority owner of Telespazio, a provider of satellite technology and services.

“Resilient, secure, and scalable space infrastructure and space data networks are vital to customers who want to push farther on the lunar surface and beyond to Mars,” Steve Altemus, co-founder and CEO of Intuitive Machine, said in a news release.

Massimo Claudio Comparini, managing director of Leonardo’s space division, added that the partnership with Intuitive Machines is a big step toward enabling human and robotic missions from the U.S., Europe and other places “to access a robust communications network and high-precision navigation services while operating in the lunar environment.”

Intuitive Machines recently expanded its Houston Spaceport facilities to ramp up in-house production of satellites. The company’s first satellite will launch with its upcoming IM‑3 lunar mission.

Intuitive Machines says it ultimately wants to establish a “center of space excellence” at Houston Spaceport to support missions to the moon, Mars and the region between Earth and the moon.