Should your startup opt for SAFEs or convertible notes on your next funding round? This Houston expert weighs in. Photo via Getty Images

As both a founder and occasional early-stage investor in the Houston ecosystem, I've seen firsthand the opportunities and challenges surrounding seed funding for local startups. This critical first fundraising round sets the trajectory, but navigating the landscape can be tricky, especially for first time founders who may not be familiar with the lingo.

One key dynamic is choosing the right deal structure — SAFEs (Simple Agreement for Future Equity) vs. convertible notes are the most common vehicles early stage startups use to raise capital and are far more founder-friendly than a priced round.

Let's start first with what the have in common:

  • Both allow you to defer setting a valuation for your company until a later (likely priced) round, which is useful in early stages or pre-revenue companies
  • Both are cheaper and faster to execute than a priced round, which cash-strapped early stage founders like
  • Both can have terms like valuation cap, discount, conversion event, and pro rata rights.
  • Both are less attractive to investors seeking immediate equity (especially important if starting the QSBS clock is part of your investors strategy or if the investor is newer to startup investing)
  • Both can create messy cap tables and the potential for a lot of dilution for the founders (and investors) if they are used for multiple raises (especially with different terms)

While as you can see they have similarities, they have some important differences. Let's dig in on these next:

SAFEs:

  • Created by Y Combinator in 2013, the intent was to create a simplified, founder friendly agreement as an alternative to the convertible note
  • Is an agreement for future equity for the investor at a conversion event (priced round or liquidation event) which converts automatically.
  • It's not a debt instrument and does not accrue interest or have a maturity date.
  • Generally have much lower upfront legal costs and faster to execute

Convertible Notes:

  • A debt agreement that converts to equity at a later date (or conversion event like a priced round)
  • Accrues interest (usually 2 to 8 percent) and has a maturity date by which the note must either be repaid or convert to equity. If you reach your maturity date before raising a qualifying round, you can often renegotiate to extend the maturity date or convert the note, though be prepared to agree to higher interest rates, additional warrants, or more favorable conversion terms.
  • More complex and take longer to finalize due to non-standard terms resulting in higher legal and administrative costs

It's worth reiterating that in both cases, raising multiple rounds can lead to headaches in the form of complex cap tables, lots of dilution, and higher legal expenses to determine conversion terms. If your rounds have different terms on discounts and valuation caps (likely) it can cause confusion around equity and cap table structure, and leave you (the founder) not sure how much equity you will have until the conversion occurs.

In my last startup, our legal counsel — one of the big dogs in this space for what it's worth — strongly advised us to only do one SAFE round to prevent this.

Why do some investors tend to prefer convertible notes?

There are a few reasons why some investors, particularly angel investors from developing startup ecosystems (like Houston), prefer convertible notes to SAFEs.

  • Because they are structured as debt, note holders have a higher priority than equity investors in recovering their investment if the company fails or is liquidated. This means they would get paid after other creditors (like loans or credit cards) but before equity investors, increasing the likelihood of getting some of their money back.
  • The interest terms protect investors if the founder takes a long time to raise a priced funding round. As time passes, interest accumulates, increasing the investor's potential return. This usually results in the investor receiving a larger equity stake when the note converts. However, if the investor chooses to call in the note instead, the accrued interest would increase the amount of money owed, similar to a traditional loan
  • More defined conversion triggers (including a maturity date) gives investors more control and transparency on when and how their investment will convert.
  • Can negotiate more favorable terms than the standard SAFE agreement, including having both a valuation cap and a discount (uncommon on a SAFE, which usually only has one or the other), interest rates, and amendment clauses to protect them from term revisions on earlier investors by future investors (called a cram-down), etc.
We'll go over what the various terms in these agreements are and what to look out for in a future article

How to choose:

  • Consider your startup's stage and valuation certainty — really uncertain or super early? Either of these instruments are preferable to a priced round as you can defer the valuation discussion
  • Assess investor preferences in your network — often the deciding factor if you don't have a lot of leverage; most local angels prefer c-notes because they see them as less risky though SAFEs are becoming more common with investors in tech hubs like Silicon Valley
  • Evaluate your timeline and budget for legal costs — as I mentioned, SAFEs are way less expensive to execute (though still be prepared to spend some cash).
  • Align the vehicle with your specific goals and growth trajectory

There's no one-size-fits-all solution, so it's crucial to weigh these factors carefully.

The meanings of these round terms like "seed" are flexible, and the average seed funding amount has increased significantly over the past decade, reaching $3.5 million as of January 2024. This trend underscores the importance of choosing the right funding vehicle and approach.

Looking ahead, I'm bullish on Houston's growing startup ecosystem flourishing further. Expect more capital formation from recycled wins, especially once recently minted unicorns like High Radius, Cart.com, Solugen, and Axiom Space exit and infuse the ecosystem with fresh and hungry angels, new platforms beyond traditional venture models, and evolving founder demographics bringing fresh perspectives.

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Adrianne Stone is the principal product manager at Big Cartel and the founder of Bayou City Startups, a monthly happy hour organizer. This article original ran on LinkedIn.

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How a Houston company is fighting anxiety, insomnia & Alzheimer’s through waveforms

mental health

A Houston-based company is taking a medicine-free approach to target brain neurologically associated with mental illness.

Nexalin Technology’s patented, FDA-cleared frequency-based waveform targets key centers of the midbrain to support the normalization of neurochemicals through a process known as Transcranial Alternating Current Stimulation (tACS). Delivered via a non-invasive device, the treatment gently stimulates the hypothalamus and midbrain, helping to “reset networks associated with symptoms” of anxiety and insomnia. Early clinical evidence suggests this approach can promote healthier brain function and improved sleep.

Through its recently appointed scientific advisory board (SAB), Nexalin also aims to target Alzheimer’s disease with a clinical development pipeline supported by published data and internal data from studies involving its proprietary DIFS technology. Nexalin’s Gen-2 SYNC and Gen-3 Halo headset delivers the DIFS, which is a waveform that can penetrate deep brain structures implicated in cognitive decline and mental illness.

The board includes experts in neurology, neuroimaging and neurodegenerative diseases with Dr. Mingxiong Huang, Dr. David Owens, and Dr. Abe Scheer coming on board. Nexalin plans to initiate new Alzheimer’s-focused clinical studies in the Q3 2025 by incorporating cognitive testing, imaging biomarkers, and guided metrics to assess treatment efficacy and neural activation.

“I am excited to work alongside Nexalin’s leadership and fellow SAB members to help guide the next generation of non-invasive neuromodulation therapies,” Huang said in a news release. “The intersection of neuroimaging, brain stimulation, and clinical science holds enormous potential for treating neurodegenerative disease.”

Recently, Nexalin’s proprietary neurostimulation device moved forward with a clinical trial that evaluated its treatment of anxiety disorders and chronic insomnia in Brazil. The first of Nexalin’s Gen-2 15-milliamp neurostimulation devices was shipped to São Paulo, Brazil, and the study will be conducted at the Instituto de Psiquiatria University Hospital (IPq-HCFMUSP). The shipments aim to support the launch of a Phase II clinical trial in adult patients suffering from anxiety and insomnia. The Nexalin Gen-2 15-milliamp neurostimulation device has also been approved in China, Brazil and Oman. Its Gen 1 device first received FDA clearance in 2003, according to the company's website.

The company also enrolled the first patients in its clinical trial at the University of California, San Diego, in collaboration with the VA San Diego Healthcare System for its Nexalin HALO, which looks to treat mild traumatic brain injury and post-traumatic stress disorder in military personnel and the civilian population.

Nexalin previously raised $5 million through a

public stock offering.

Houston innovation hub announces first cohort for energy-focused accelerator

Powering Up

Energytech Nexus, a Houston-based hub for energy startups, has named its inaugural cohort of 14 companies for the new COPILOT accelerator.

COPILOT partners with Browning the Green Space, a nonprofit that promotes diversity, equity and inclusion (DEI) in the clean energy and climatech sectors. The Wells Fargo Innovation Incubator (IN²) at the National Renewable Energy Laboratory backs the COPILOT accelerator.

The eight-month COPILOT program offers mentorship, training and networking for startups. Program participants will be tasked with developing pilot projects for their innovations.

Two Houston startups are members of the first COPILOT class:

  • GeoFuels, housed at Houston’s Greentown Labs, has come up with a novel approach to hydrogen production that relies on geothermal power and methane decomposition.
  • PolyQor, which converts plastic waste into eco-friendly construction materials. Its flagship EcoGrete product is an additive for concrete that enhances its properties while reducing carbon emissions. PolyQor’s headquarters is at Houston’s Greentown Labs.

Other members of the COPILOT cohort are:

  • Birmingham, Alabama-based Accelerate Wind, developer of a wind turbine for commercial buildings.
  • Ann Arbor, Michigan-based Aquora Biosystems, which specializes in organic waste biorefineries.
  • Phoenix-based EarthEn Energy, a developer of technology for thermo-mechanical energy storage.
  • New York City-based Electromaim, which installs small hydro-generators in buildings’ water systems.
  • Chandler, Arizona-based EnKoat, an advanced materials company whose flagship product, the IntelliKoat System, is a patented two-layer thermal and weather barrier roof coating for flat and low-slope commercial buildings.
  • Calgary, Canada-based Harber Coatings, which manufactures electroless nickel coating and electroless nickel plating.
  • Dallas-based Janta Power, which designs and makes 3D solar towers.
  • Miami-based NanoSieve, a developer of gas remediation technology.
  • Palo Alto, California-based Popper Power, which has developed a platform that turns streetlight networks into resilient, maintenance-free distributed charging infrastructure.
  • Buffalo, New York-based Siva Powers America, developer of small wind turbines for farms, utility companies and others with annual energy needs of 300,000 to 2 million kilowatt-hours.
  • Los Angeles-based Thermoshade, which specializes in cooling panels for outdoor environments.
  • Waukesha, Wisconsin-based V-Glass, Inc., developer of a vacuum-insulated glass for affordable high-efficiency windows.

“These startups reflect the future of energy access and resilience innovation,” said Juliana Garaizar, founding partner of Energytech Nexus. “By connecting them directly with partners through COPILOT, we’re helping them overcome the ‘pilot gap’ to build solutions that scale.”

The startups will run pilot projects along the Gulf Coast for their inventions.

Rice University's top innovation exec leaving for new role at UVA

moving on

Paul Cherukuri, Rice University's top innovation executive, responsible for some of Rice’s major innovative projects like the Rice BioTech LaunchPad and Rice Nexus, will leave the university next month to accept a position at the University of Virginia.

Cherukuri, Rice’s first vice president for innovation and chief innovation officer, will become the University of Virginia’s Donna and Richard Tadler University Professor of Entrepreneurship and the school's first chief innovation officer, according to a release from Rice. Cherukuri, who has served for more than 10 years at Rice, plans to depart his current position on Sept. 30.

Adrian Trömel, associate vice president for innovation strategy and investments at Rice, will serve as interim vice president for innovation and chief innovation officer after Cherukuri departs, and as the university starts an international search for his replacement.

“We appointed Paul to build an ambitious and high-functioning innovation operation, and he has succeeded remarkably in short order,” Rice President Reginald DesRoches said in the release. “In every area, from technology translation and startup creation to commercialization and entrepreneurship training, he has led the effort to vastly improve our structure, operations and relationships. He has contributed immensely both to our strategies and their implementation across numerous areas, and we’ll miss him greatly.”

Cherukuri is a physicist, chemist and medical technology entrepreneur, and has been a member of DesRoches’ leadership team since 2022. Cherukuri served as executive director of Rice’s Institute of Biosciences and Bioengineering from 2016 to 2022, where he helped in the development of interdisciplinary translational research partnerships with federal and corporate agencies. His work helped earn nearly $37 million in funding for accelerating the development of new technologies into commercial products. In the energy transition field, Cherukuri led a $12.5 million partnership with Woodside Energy to transform greenhouse gases into advanced nanomaterials for next-generation batteries and transistors.

Initiatives the Rice Biotech Launch Pad, an accelerator focused on expediting the translation of the university’s health and medical technology; RBL LLC, a biotech venture studio in the Texas Medical Center’s Helix Park dedicated to commercializing lifesaving medical technologies from the Launch Pad; and Rice Nexus, an AI-focused "innovation factory" at the Ion; were all launched under Cherukuri’s leadership. With his work at the Ion, Cherukuri also led the announcement of a partnership with North America’s largest climate tech incubator, Greentown Labs.

“I am proud of the relentless innovative spirit we have built for Rice in Houston and around the world,” Cherukuri said in the release. “I look forward to bringing new energy and vision to UVA’s efforts in this critical space for our country, its success and future.”