The defense-tech sector is a whole lot more than just drones — and it's diversifying by the day.The big picture: The Silicon Valley Defense Group's latest inventory of prominent private-capital-backed companies and their contracts, known as the NatSec100, bears this out.The top quartile, bracketed by Anduril Industries and Blue Origin, includes makers of autonomous boats and hypersonic missiles as well as a serial factory specialist, plus a quantum computer.Keep scrolling and you'll see nuclear batteries, secure communications, ground autonomy, augmented reality for pilots and lunar rovers.More than a third of the list appears for the first time. Meantime, a dozen previous listees, including Hawkeye 360 and Kodiak Robotics, have gone public.What they're saying: "When we started this — and this is a bit of an exaggeration — there was a little bit more of a challenge to come up with 100 companies. Now, the challenge is to fit the top 100 companies," Mike Keating, the executive director of SVDG, told Axios."We have companies that aren't in the top 100 that have deployed technologies as part of Epic Fury. They're in the field in Ukraine," he added."The reality is the private-capital appetite is voracious. It's not going down."Follow the money: In-Q-Tel, which recently reworked its investment strategy, backed 33 companies in this year's rankings.Alumni Ventures backed 25. Washington Harbour Partners, 16. Andreessen Horowitz, 15. Lockheed Martin Ventures, 14. BlackRock, 11."Last year alone we invested over three-quarters of a billion dollars in the defense-industrial base," Mina Faltas, the founder of Washington Harbour Partners, told Axios. (He specifically cited space, nuclear energy and AI.)"Our view is that private capital and the public sector, that PE and VC, that primes and system integrators, that startups and neo-primes should work together as a community."Yes, but: These contractors still aren't winning major chunks of Defense Department spending. As the Defense Tech and Acquisition blog noted: "Our topline takeaway is that the NatSec100 companies still only received a pittance (0.5%) of DoW contract obligations last year."What we're watching: Whether a $1.5 trillion defense budget, as promised by President Trump and Defense Secretary Pete Hegseth, trickles down to the smaller startups.The intrigue: JPMorgan sponsored this year's NatSec100.The financial institution in late 2025 launched a $1.5 trillion defense investment initiative. Months later, it expanded to Europe.The bottom line: Merritt Ogle, the SVDG chief operating officer, told Axios the number of companies eligible to make the list had roughly quadrupled over the last four years, from around 300 to 1,200."There is a much larger mix here at play."More from Axios:The booms and bombs of defense-tech investingPentagon's "Deal Team Six" has big-money ambitionsAmerican Dynamism and its defense tech descend on D.C.