This month, Mark Walker is celebrating his company's one year anniversary of going public — only the ninth Black-founded business to accomplish this feat on a U.S. stock exchange. Photo courtesy

After working in both sides of the advertising world, Mark Walker thought he could reimagine a platform that would be more efficient and equitable.

Walker co-founded his company, Direct Digital Holdings, an adtech platform, after serving in several roles — from an early hire at Houston digital media startup Questia to business development director at NRG Energy and COO of EBONY Media. He shares on the Houston Innovators Platform how he took this experience in tech, advertising, and media to create his company's platform.

"NRG Energy gave me a top-down view of the value chain, and Ebony gave me a bottoms-up view of the value chain of how media is purchased," Walker says on the show. "At Direct Digital Holdings, we help companies buy and sell media — and we leverage technology to do it. It's really the culmination of both of those experiences."

With over 30,000 publishers on its platform, Direct Digital makes it easier for its core customers — middle market companies looking to buy into the digital media ecosystem — to tap into these opportunities without the tech know-how they might otherwise need. Walker explains that at EBONY, he saw how small to midsize publications — especially the multicultural ones — were being left out on the ad selling side of the equation. The Direct Digital platform bridges the gap on each end.

Founded in 2018 in partnership with Keith Smith, who went through similar professional experiences, Direct Digital went public exactly one year ago after growing the company through strategic M&A activity. Walker says the decision to IPO made the most sense for his company — though it wasn't an easy process. Direct Digital is only the ninth company founded by a Black entrepreneur to go public on a US stock exchange.

"If you think the process is hard — it actually is," Walker says on the journey to IPO. "We were a privately held company, and we knew we had a good growth trajectory and we looked a couple different options. We decided to go public in a very traditional way."

Walker explains there were some risks involved, but the co-founders ultimately decided to shy away from adding in investors who might not have the same ideas for the company's future.

Direct Digital has been a Houston company from the star — despite the city not being home to a booming adtech ecosystem. Instead, Houston — with its collection of Fortune 500 companies and rich diversity — has allowed the business to stand out.

"If you look at and reflect on how our company has been built — from our board of directors to our leadership and management team — we're a majority minority organization all the way across the board," Walker says. "Diversity is very important to us. It's the lifeblood of our business — especially because we're serving publishers in those communities in big way. And moreso, we think you get the best product, thoughts, and ideas from a diverse workforce, and Houston fits right into that mold for us."

Walker shares more about his company's future, advice on IPO, and what all he's watching in adtech — from AI to streaming — on the podcast. Listen to the interview below — or wherever you stream your podcasts — and subscribe for weekly episodes.


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Houston company ranks No. 13 worldwide on Forbes Global 2000 list

World's Biggest Companies

More than 60 Texas-based companies appear on Forbes’ 2025 list of the world’s 2,000 biggest publicly traded companies, and nearly half come from Houston.

Among Texas companies whose stock is publicly traded, Spring-based ExxonMobil is the highest ranked at No. 13 globally.

Rounding out Texas’ top five are Houston-based Chevron (No. 30), Dallas-based AT&T (No. 35), Austin-based Oracle (No. 66), and Austin-based Tesla (No. 69).

Ranking first in the world is New York City-based J.P. Morgan Chase.

Forbes compiled this year’s Global 2000 list using data from FactSet Research to analyze the biggest public companies based on four metrics: sales, profit, assets, and market value.

“The annual Forbes Global 2000 list features the companies shaping today’s global markets and moving them worldwide,” said Hank Tucker, a staff writer at Forbes. “This year’s list showcases how despite a complex geopolitical landscape, globalization has continued to fuel decades of economic growth, with the world’s largest companies more than tripling in size across multiple measures in the past 20 years.”

The U.S. topped the list with 612 companies, followed by China with 317 and Japan with 180.

Here are the rest of the Texas-based companies in the Forbes 2000, grouped by the location of their headquarters and followed by their global ranking.

Houston area

  • ConocoPhillips (No. 105)
  • Phillips 66 (No. 276)
  • SLB (No. 296)
  • EOG Resources (No. 297)
  • Occidental Petroleum (No. 302)
  • Waste Management (No. 351)
  • Kinder Morgan (No. 370)
  • Hewlett Packard Enterprise (No. 379)
  • Baker Hughes (No. 403)
  • Cheniere Energy (No. 415)
  • Corebridge Financial (No. 424)
  • Sysco (No. 448)
  • Halliburton (No. 641)
  • Targa Resources (No. 651)
  • NRG Energy (No. 667)
  • Quanta Services (No. 722)
  • CenterPoint Energy (No. 783)
  • Coterra Energy (No. 1,138)
  • Crown Castle International (No. 1,146)
  • Westlake Corp. (No. 1,199)
  • APA Corp. (No. 1,467)
  • Comfort Systems USA (No. 1,629)
  • Group 1 Automotive (No. 1,653)
  • Talen Energy (No. 1,854)
  • Prosperity Bancshares (No. 1,855)
  • NOV (No. 1,980)

Austin area

  • Dell Technologies (No. 183)
  • Flex (No. 887)
  • Digital Realty Trust (No. 1,063)
  • CrowdStrike (No. 1,490)

Dallas-Fort Worth

  • Caterpillar (No. 118)
  • Charles Schwab (No. 124)
  • McKesson (No. 195)
  • D.R. Horton (No. 365)
  • Texas Instruments (No. 374)
  • Vistra Energy (No. 437)
  • CBRE (No. 582)
  • Kimberly-Clark (No. 639)
  • Tenet Healthcare (No. 691)
  • American Airlines (No. 834)
  • Southwest Airlines (No. 844)
  • Atmos Energy (No. 1,025)
  • Builders FirstSource (No. 1,039)
  • Copart (No. 1,062)
  • Fluor (No. 1,153)
  • Jacobs Solutions (1,232)
  • Globe Life (1,285)
  • AECOM (No. 1,371)
  • Lennox International (No. 1,486)
  • HF Sinclair (No. 1,532)
  • Invitation Homes (No. 1,603)
  • Celanese (No. 1,845)
  • Tyler Technologies (No. 1,942)

San Antonio

  • Valero Energy (No. 397)
  • Cullen/Frost Bankers (No. 1,560)

Midland

  • Diamondback Energy (No. 471)
  • Permian Resources (No. 1,762)
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A version of this article originally appeared on CultureMap.com.

Texas plugs in among states at highest risk for summer power outages in 2025

hot, hot, hot

Warning: Houston could be in for an especially uncomfortable summer.

A new study from solar energy company Wolf River Electric puts Texas at No. 2 among the states most at risk for power outages this summer. Michigan tops the list.

Wolf River Electric analyzed the number of large-scale outages that left more than 5,000 utility customers, including homes, stores and schools, without summertime electricity from 2019 to 2023. During that period, Texas experienced 7,164 summertime power outages.

Despite Michigan being hit with more summertime outages, Texas led the list of states with the most hours of summertime power outages — an annual average of 35,440. That works out to 1,477 days. “This means power cuts in Texas tend to last longer, making summer especially tough for residents and businesses,” the study says.

The Electric Reliability Council of Texas (ERCOT), which operates the electric grid serving 90 percent of the state, predicts its system will set a monthly record for peak demand this August — 85,759 megawatts. That would exceed the current record of 85,508 megawatts, dating back to August 2023.

In 2025, natural gas will account for 37.7 percent of ERCOT’s summertime power-generating capacity, followed by wind (22.9 percent) and solar (19 percent), according to an ERCOT fact sheet.

This year, ERCOT expects four months to surpass peak demand of 80,000 megawatts:

  • June 2025 — 82,243 megawatts
  • July 2025 — 84,103 megawatts
  • August 2025 — 85,759 megawatts
  • September 2025 — 80,773 megawatts

One megawatt is enough power to serve about 250 residential customers amid peak demand, according to ERCOT. Using that figure, the projected peak of 85,759 megawatts in August would supply enough power to serve more than 21.4 million residential customers in Texas.

Data centers, artificial intelligence and population growth are driving up power demand in Texas, straining the ERCOT grid. In January, ERCOT laid out a nearly $33 billion plan to boost power transmission capabilities in its service area.

Houston ranks among top 5 cities for corporate HQ relocations in new report

h-town HQ

The Houston area already holds the title as the country’s third biggest metro hub for Fortune 500 headquarters, behind the New York City and Chicago areas. Now, Houston can tout another HQ accolade: It’s in a fourth-place tie with the Phoenix area for the most corporate headquarters relocations from 2018 to 2024.

During that period, the Houston and Phoenix areas each attracted 31 corporate headquarters, according to new research from commercial real estate services company CBRE. CBRE’s list encompasses public announcements from companies across various sizes and industries about relocating their corporate headquarters within the U.S.

Of the markets included in CBRE’s study, Dallas ranked first for corporate relocations (100) from 2018 to 2024. It’s followed by Austin (81), Nashville (35), Houston and Phoenix (31 each), and Denver (23).

According to CBRE, reasons cited by companies for moving their headquarters include:

  • Access to lower taxes
  • Availability of tax incentives
  • Proximity to key markets
  • Ability to support hybrid work

“Corporations now view headquarters locations as strategic assets, allowing for adaptability and faster reaction to market changes,” said CBRE.

Among the high-profile companies that moved their headquarters to the Houston area from 2018 to 2024 are:

  • Chevron
  • ExxonMobil
  • Hewlett-Packard Enterprise
  • Murphy Oil

Many companies that have shifted their headquarters to the Houston area, such as Chevron, are in the energy sector.

“Chevron’s decision to relocate its headquarters underscores the compelling advantages that position Houston as the prime destination for leading energy companies today and for the future,” Steve Kean, president and CEO of the Greater Houston Partnership, said in 2024. “With deep roots in our region, Chevron is a key player in establishing Houston as a global energy leader. This move will further enhance those efforts.”

According to CBRE, California (particularly the San Francisco Bay and Los Angeles areas) lost the most corporate HQs in 2024, with 17 companies announcing relocations—12 of them to Texas. Also last year, Texas gained nearly half of all state-to-state relocations.

In March, Site Selection magazine awarded Texas its 2024 Governor’s Cup, resulting in 13 consecutive wins for the state with the most corporate relocations and expansions.

In a news release promoting the latest Governor’s Cup victory, Gov. Greg Abbott hailed Texas as “the headquarters of headquarters.”

“Texas partners with the businesses that come to our great state to grow,” Abbott said. “When businesses succeed, Texas succeeds.”

CBRE explained that the trend of corporate HQ relocations reflects the desire of companies to seek new environments to support their goals and workforce needs.

“Ultimately, companies are seeking to establish themselves in locations with potential for long-term success and profitability,” CBRE said.