Arthur Karell (First In) / VC Breakdown & Contact

About Arthur Karell

Arthur Karell is a venture capital partner at First In who combines an unusually decorated front-line combat background as a Marine Corps infantry officer with Bronze Star recognition, Big Law training, and senior operating roles at high-growth defense and policy tech companies including FiscalNote, Anduril, and co-founding Seashell. He personally sourced and closed over $425M in strategic acquisitions at Anduril in under two years, giving him rare hands-on M&A experience at a flagship defense-tech unicorn before becoming a seed-stage investor focused on defense and dual-use technologies.

Where they've Worked

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Arthur Karell's Interests

What they've been talking about across their social media accounts

Highly focused on defense technology and modernizing military operations. Actively champions startups building advanced national security hardware and software, pointing to companies developing hypersonic projectiles or software that replaces legacy military presentation formats for tactical mission planning.
Deeply interested in cybersecurity and resilient communications infrastructure. Frequently highlights the urgent need to protect commercial networks alongside artificial intelligence data centers, specifically emphasizing investments in zero trust security architecture and modern network routing protocols.
Passionate about veteran career transitions and the American industrial base. Strongly supports programs that integrate former military personnel into the civilian workforce, recently highlighting an organization that trains and credentials veterans as expert machinists and welders to bolster domestic manufacturing.
Tracking major artificial intelligence infrastructure and its massive energy demands. Keeps a close eye on the capital required to build out global computing power, noting immense multi billion dollar investments and the massive power grid requirements needed to support modern data centers.
Attentive to decentralized finance and the digital asset regulatory landscape. Regularly discusses decentralized financial platforms and web security, having previously highlighted startups working to democratize financial products while monitoring how federal regulators handle digital asset bank charters.
Engaged with global macro trends using geospatial intelligence and supply chain data. Analyzes global trade competition and energy supply shifts by looking at real time maritime traffic data and commercial satellite imagery from providers tracking oil tankers and global shipping routes.

Video Interview

On the most overlooked slide in a pitch deck

"A campaign is a thoughtful approach to like, by doing this next thing, it's going to unlock this next thing, and it's going to unlock this other thing. And having seen a founder kind of think through that in sequence and also having shown that whatever the first one or two steps are that they're either completed or they're in progress, that's a great signal."

Arthur Karell

Partner, First In

On why market sizing slides are overrated

"If you can dominate a small market, that puts you in a position to make a whole series of decisions and being able to open a number of doors to much larger markets from there, even though that initial market may have struck you or struck another investor as fairly small."

Arthur Karell

Partner, First In

On what clarity in a pitch deck actually means

"A clear pitch deck is what matters. I would absolutely index the clarity of thought... that pitch deck could be black text on white, if it's a clear argument for making the investment, nailed it."

Arthur Karell

Partner, First In

On the biggest red flag in early conversations

"Time kills all deals. And that is one that's a thousand percent accurate for especially venture capital firms... If it's taking you quite some time to get back to an investor with the materials you said you were going to have, it's not a great look."

Arthur Karell

Partner, First In

On the most common mistake right after closing a round

"Speed is your only advantage. If you think that closing that round is kind of like you hit the finish line, like we can coast for a bit, that is absolutely the wrong answer. Closing of the funding, that's the starting."

Arthur Karell

Partner, First In

About their Fund

First In

Sectors

Cybersecurity, Defense, Data, Deeptech / Hardware, AI

Rounds

Seed

Avg Check Size

$500K - $2M

Notable Investments

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First In is a venture capital fund led by former Marine Corps officers, CIA operatives, and defense-tech operators who apply military systems thinking to invest in early-stage security technologies across cyber, defense, data, and critical infrastructure. The firm targets founders comfortable building at the intersection of national security and commercial markets, backing companies like Anduril and Shift5 that directly shape national defense capabilities rather than typical enterprise software tools.

Other partners at the fund