Catalyst N° 092 of 125 8 Jan 2026
The VC case for ‘full stack deeptech’
with Ian Rountree, founder and partner, Cantos
In this note
The question
Which hard technology startups are actually investable at venture pace, and which ones are structurally set up to fail no matter how good the technology is?
The answer
Rountree’s rule is that the technology is never the asset. A startup gets roughly 18 months to show enough progress to raise again, so any company whose route to revenue runs through a slow incumbent’s purchasing process is dead on arrival, however much better its product is. What he backs instead are companies that own their end product, selling the good or even the commodity rather than the technology inside it, accepting more capital intensity in exchange for speed and value capture. Kann agrees with the thesis and notes that it excludes the large majority of startups in energy and industrials.
03The argument
Start with the pass that matters most, selling technology to incumbents, which is what most deep tech startups in industrial categories do because the incumbents own the infrastructure and the distribution. Rountree says it looks like the easy path precisely because it scopes the company down to productizing one piece of technology for one big buyer. What kills it is not that you lose the argument; it is the clock. Founders raise serially, typically 18 to 24 months of runway, and have to start fundraising about six months before the money runs out, which leaves roughly 18 months to produce whatever the next round requires. If the customer’s sales cycle is longer than that, the company is dead by arithmetic rather than by merit. His example is a 2016 investment with strong machine learning and interoperability software selling into carmakers, which died with good investors and good people because Ford and Toyota purchasing outlasted the round. Kann adds pilot purgatory: big companies happily pilot, and the gap between pilot and commercial rollout is never a knowable number. Rountree’s practical advice is to work out how the buyer is personally compensated, because incentives explain most otherwise baffling behavior and tell you whether the sales cycle is compatible with your company at all.
The second reason is price rather than time. Even where an incumbent agrees the technology is ten times better and wants it, the offer comes in far below what the seller thinks it is worth, and pushing back does not move it; if you are not in the pole position you do not get paid for the value you create. That leads into the second pass, commercializing science. Rountree’s view is that a business exists to earn margins above its cost of capital and technology is only a means to that, so being mind-blowing and widely cited is not the same as being economically valuable. The founder failure mode he describes is a hammer looking for nails, common among people commercializing their own doctoral work, when the discipline required is obsession with a problem and indifference about the solution. There is also a timing objection: he would rather fund a novel application of an existing technology than wait for something to climb the maturity ladder, and says he has lost money waiting. Fusion is the clean test case, and he is explicit that he does not invest in it and cannot wait for it, while hoping for humanity’s sake that it works. The exception he grants is biology and pharmaceuticals, where the steps are standardized enough that an entire capital market has learned to underwrite technical maturity, and large pharmaceutical acquirers buy on a discounted cash flow rather than on technical milestones. Kann asks why that cannot be copied elsewhere; the answer is that no other field is scientifically and regulatorily defined enough for a capital market to form around it.
The positive archetype follows from all of that. Full stack is borrowed from a 2015 Chris Dixon post at Andreessen Horowitz about companies like Uber, Lyft and Airbnb that used software to reshape an industry instead of selling software to it, extended here to companies that build physical things as well. The operative half is selling the end product: work out who buys the thing your technology improves, and sell them that thing. Mining is the worked example. Startups offering satellite imagery and AI to help miners find deposits found that miners would not pay much, so Earth AI, one of Cantos’s largest investments, bought mineral rights, hired geologists and drilled its own hypotheses, and now holds deposits rather than a software licence. That costs more capital and more operational risk. Commodities, usually a venture pejorative, are for the same reason his favourite case. He frames a startup as carrying technical, execution and market risk, and argues that if you are taking extra technical risk in hard tech you must offset it with less market risk or you are simply making worse investments. A product molecularly identical to its competitors’ but cheaper to make has essentially no market risk, because the spot price tells you exactly what you have to beat. Kann qualifies this, noting commodities are less fungible than they look, since where and when an electron is delivered matters enormously, and points to Crusoe as a company whose differentiated input, flare gas, gave it a structural advantage in a commodity business.
The second archetype, the weird company with no comparables, gets the thinnest support in the conversation. The rationale is competitive rather than technical: in a crowded area you fight other companies for talent and capital, whereas a genuinely singular company pulls both toward itself. The evidence offered is two anecdotes, and Rountree concedes that weird usually means controversial, so the strategy requires disagreeing with people. Both archetypes raise the bar on the founder rather than lowering it, since vertical integration means raising more money, so he looks for people who are both real technologists and fluent enough to pull capital toward them. It is worth being precise about what this frame is and is not. It is a rule for what produces venture-scale returns on a pre-seed fund’s clock, not a claim about which technologies matter, which is why fusion can be both a pass and something he hopes succeeds.
04What you need to know first
- The 18-month clock
- Startups raise in rounds, typically 18 to 24 months of cash, and must start raising again about six months before the money is gone. Almost every judgement in this episode reduces to whether something can be proved inside that window.
- Full stack
- Building and selling the end product yourself rather than selling your technology to whoever currently sells that product. More capital and more operational risk, in exchange for speed and value capture.
- Technical risk versus market risk
- Whether the thing will work, versus whether anyone will buy it. Rountree’s portfolio rule is that extra technical risk has to be paid for with less market risk.
- Technology readiness levels
- The staged scale for how proven a technology is, from laboratory result to field-ready. Rountree’s complaint is that waiting for a company to climb it burns the clock, and his pharmaceutical exception is that capital markets there have learned to price positions on that ladder.
05Details worth keeping
- The 2016 automotive software investment is his cautionary tale: real technology, good investors, good people, killed by the length of carmakers’ sales cycles.
- His diagnostic for incomprehensible corporate behaviour is to find out how the person is paid. Once you know the incentive you can sometimes shorten the cycle, and can at least tell whether to start it.
- Best technology does not win on its own. A Cantos radar company he considers technically superior, cheaper than a camera and able to see through fog, is being beaten by Chaos Industries, which he thinks has worse technology but more capital and much better productization and selling. He hopes to catch up and says he has seen this movie before.
- His line for that dynamic: you can be objectively right, but if everyone else is wrong for long enough you are effectively wrong, and the market can stay wrong longer than you can afford to be right.
- Kann’s example of the hammer-in-search-of-a-nail problem is metal fuels, where one combustion professor produced a diaspora of startups all using combustion, which Kann considers clearly the worse approach.
- The two weird-company examples are a former Wall Street banker using satellite imagery and AI to find fossils, which Rountree calls De Beers for dinosaurs, and Kann’s mention of Colossal Biosciences and the woolly mammoth.
- Kann offers a frame of wave makers, who cause something that would not otherwise have happened, against wave riders, who correctly call a trend. Rountree does not take up the distinction and answers on founder type instead.
06Claims worth citing
All as stated on 2026-01-08. This episode is mostly heuristics rather than numbers, and the few figures are the speaker’s rules of thumb.
- Startups raise 18 to 24 months of runway and must begin fundraising about six months before it runs out, leaving roughly 18 months of working time; a customer sales cycle longer than that makes the company de facto dead. Rountree
- Cantos was founded nearly 10 years before the recording, with first investments in 2016. Rountree
- Full stack is taken from a 2015 Chris Dixon post at Andreessen Horowitz describing companies such as Uber, Lyft and Airbnb. Rountree
- Earth AI is one of Cantos’s largest investments and now owns deposits the firm believes are very valuable. This is an investor’s assessment of his own position; no production, sale or third-party valuation is mentioned. Rountree
- Large pharmaceutical acquirers buy on discounted cash flow analysis rather than technical milestones, which is what lets a capital market underwrite technical maturity in that sector and not in others. Rountree
- Taking technical risk but not market risk is attributed to Vinod Khosla. Khosla, paraphrased by Kann
- Crusoe went from flare gas to bitcoin mining to building large data center campuses for OpenAI and Oracle, offered as a commodity business with a differentiated input. Kann
07Where it’s contested
- Almost nothing is contested, and that is worth recording. This is two early-stage investors agreeing on a shared thesis. Kann opens by saying he could not agree more strongly, and the conversation elaborates the thesis rather than testing it. No operator, founder or sceptic is present.
- Kann states the thesis’s own limit. He says it describes a world that excludes the vast majority of startups in energy and industrials, which is a statement about what the rule filters out rather than an argument that those companies are worthless.
- The fusion pass is scoped narrowly by the guest himself. He says it is expressly not the kind of science Cantos invests in because he cannot wait for it, and separately that he hopes it is achieved. It is a verdict on fit with a pre-seed fund’s timeline, not on the technology.
- He supplies his own counterexample. The radar company shows better technology losing to better capitalization and better productization. His answer is a hope of catching up, which he undercuts in the same breath.
- Earth AI’s value is unrealized and self-assessed. Owning deposits believed to be valuable is a different claim from having sold anything.
- The weird-company archetype rests on the least evidence in the episode: a competition-for-capital argument plus two anecdotes, one of them a company he had only recently encountered.
- The capital intensity objection is acknowledged rather than answered. Full-stack companies need more money; Rountree’s reply is a preference for making time an ally rather than treating capital and time as a straight trade-off, which is a judgement rather than evidence.