In Thrive Capital’s first-ever investor letter, founder Joshua Kushner has some unexpected things to say about his venture capital rivals on the West Coast.

“It is difficult to overstate the magnitude of the opportunity,” Kushner wrote about AI in the letter, leaked to Bloomberg. “It would also be a grave error in our minds to let excitement weaken our investment discipline. … Within Silicon Valley in particular, the industry can become fixated on hyperincremental technological turns rather than where the technology ultimately leads.”

While his secretive New York-based firm, just like those in Silicon Valley, is betting heavily on AI, Thrive is doing so differently, he argues. There’s no so-called spray-and-pray investing. Thrive tends to goes big on the companies it backs. Bloomberg estimates about 90% of its capital is poured into the top 15 investments in each fund.

That makes Thrive, he contends, a company of independent thinkers. “We are independent because markets move between fear and enthusiasm, and neither is a substitute for judgment.”

His comments are in direct contrast to one of the basic premises of Silicon Valley venture capital: that it is a business of “outliers” as espoused by Marc Andreessen.

In the “outlier” view, a VC firm makes a lot of bets prepared to lose money on many — even most — of them. The few big hits will be so lucrative that they will cover the losers and much, much more. That philosophy leaves VCs forever looking for the next OpenAI or another mega hit. It can also lead to, as we saw during the post-pandemic lean years, cutting ongoing support for startups not deemed to be on track to be the biggest winners.

In contrast, Kushner writes, “We believed an investment firm could be opportunistic across stage, sector, and geography, while remaining deeply concentrated in a small number of people and ideas.” The idea is to “build Thrive to concentrate our time, capital, and energy on the people and ideas we believe in most.”

He also dismisses Silicon Valley’s idea that VCs are in the business of disrupting incumbents.

“Unlike many of our peers, our conviction was not only that these industries would be disrupted from the outside in but also that many would be transformed from the inside out,” he wrote about AI’s impact.

Thrive has largely stuck to this thesis. Its deepening relationship with OpenAI is its biggest example. The VC firm is a major investor in the AI lab. But in December 2025, the roles switched when OpenAI took an ownership stake in Thrive Holdings, the VC firm’s spinout. Thrive Holdings buys companies and then works with OpenAI to give them an AI makeover. Part of the deal involved OpenAI dedicating employees to work with Thrive’s companies.

Thrive Holdings has bought more than 70 businesses and has a team of 35 engineers. Kushner says its accounting platform uses agents to produce tax returns 30% faster with 98% accuracy, and its IT services firm has agents independently solving half of its help desk tickets.

Still, Thrive’s strategy is working in part because it nabbed stakes in some of the industry’s best-performing startups ever. Its $516 million 2022 early-stage fund, for instance, made early bets on OpenAI, Anduril, and SpaceX, and is now worth more than $3.7 billion as of the end of June, Bloomberg reports. Thrive has, over its 15 years, increased its stakes in all of them (and also had a sizeable stake in Cursor, which just closed its sale to SpaceX).

It has also backed Wiz, Ramp, and Stripe, to name a few other big names. Plus, it has led seed investments in new labs like Essential AI, founded by former Google Brain researcher Ashish Vaswani, the lead writer of the famed “Transformers” paper that spawned today’s AI industry.

All told, Thrive has $60 billion of assets under management, Kushner revealed in the letter. He reports impressive profits: a gross internal rate of return (IRR) across all funds of 41% and a net IRR of 33%. Thrive has returned more than $1 billion of liquidity to its investors in the last 12 months alone, he said.

“There may be an opportunity for billions of dollars in additional liquidity in the coming quarters,” he promises.

He doesn’t specify which companies are headed for their exits but obviously, the SpaceX IPO was a start, and OpenAI is working toward its own public debut.

It should be pointed out that both Kushner’s and Andreessen’s approaches obviously work in terms of making money. Andreessen Horowitz returned $25 billion to its investors between 2009 and 2025, according to the last leaked returns, reported by Eric Newcomer.

Thrive’s philosophy of concentrating capital may not even be possible for most smaller, scrappy emerging seed funds, whose founders weren’t born into the kind of access that the son of a billionaire New York real-estate family has.

That said, Kushner’s general premise of how overheated Silicon Valley’s AI investing has become isn’t wrong either. As he puts it: “Not every fast-growing business is exceptional. And not every exceptional company is a great investment at every price. Our responsibility is to maintain those distinctions.”

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Aircraft, ships and vehicles now carry many radio systems in a small space, so designers must know how much energy leaks from one antenna into another before any hardware is built. This leakage is described by the mutual s-parameters between the antenna ports, and it decides whether two systems can operate at the same time on the same platform. Measuring it by trial and error at every candidate position is slow and costly. Predicting it by simulation is difficult for two reasons. First, the platform is electrically large, which means that its dimensions span several hundreds of wavelengths, so the model needs a large number of unknowns. Second, the coupling levels of interest are very low, in some cases down to -100 dB, which leaves little margin for numerical error. This White Paper addresses both problems with a full-wave solution based on the Method of Moments applied to the Surface Integral Equation, using higher-order basis functions to keep the number of unknowns low. Two examples are studied in detail: a metallic cube carrying two quarter-wavelength monopoles, and a realistic airliner carrying five monopoles at 1.06 GHz, where the fuselage is about 140 λ long. Three modelling techniques for obtaining accurate low-level results are compared in terms of accuracy and the number of unknowns each one requires, and the complete geometry of each model is documented so that every result can be checked independently.

Since the end of last month, several water utilities in the United States have been hit by cyberattacks, causing alarm in the country. 

For years, water utilities and other critical infrastructure facilities in the power sector, for example, have been targeted by hackers, whether government-backed or individuals. What makes this recent series of attacks—allegedly carried out by Iran—particularly concerning was how widespread they have been, hitting targets in around a dozen states. 

The U.S. has more than 150,000 water systems, some of them run by local companies. In theory, that should make it harder for hackers to target several facilities at the same time. But on the flip side, the companies running these systems may not have the resources or cybersecurity expertise needed to protect themselves. 

Cybersecurity experts have long believed that Iranian hackers target low-hanging fruit in opportunistic isolated attacks, so this hacking campaign could be a significant escalation. 

A lot has happened since news of the initial attacks broke two weeks ago. So we decided it was a good time to recap what we know so far, and what we don’t. 

Where have there been attacks?

On July 28, Minnesota authorities announced that water treatment plants in more than 30 communities were hit by coordinated cyberattacks. 

Two days later, the FBI said water and wastewater utility companies in “at least seven states” reported incidents, and in some cases the attacks “degraded water operations.” Since then, apart from Minnesota, there have been reported hacks against water facilities in Arkansas, Georgia, New Jersey, and Michigan. 

Who is behind the attacks?

The short answer is: we don’t know yet, but the number one suspect is the Iranian government. 

As of today, officially, the U.S. government has yet to name the culprit behind the coordinated wave of hacks.

However, the first incidents in Minnesota came days after the U.S. Cybersecurity and Infrastructure Security Agency (CISA) warned that Iranian hackers were targeting internet-connected devices in water systems and the energy sector, without saying where those attacks were occurring. (CISA had originally published this warning in April, and updated it before the Minnesota attacks.) 

After the initial wave was uncovered in Minnesota, President Donald Trump said he did not think “there was an Iranian cyberattack.” Instead, he blamed the state, perhaps because it is run by democratic governor Tim Walz, who was chosen as Kamala Harris’s vice president in the 2024 elections.

Trump’s claim came a day after Wired reported that the Water Information Sharing and Analysis Center, or WaterISAC, a nonprofit group that distributes cybersecurity information among the water sector, told its members that the recent attacks “aligned” with the hacking campaign CISA warned of—effectively accusing the Iranian government.  

Earlier this week, The Washington Post reported that U.S. intelligence agencies “are confident” that Iran, and in particular the Islamic Revolutionary Guard Corps (IRGC), is responsible. The attribution isn’t public yet, according to the paper’s sources, because the agencies are not sure which specific unit within the IRGC was responsible, and also because officials may be reluctant to contradict Trump’s claim.

Iranian government hackers have a history of targeting critical infrastructure in the U.S., and it’s possible that these attacks are part of its strategy to retaliate against the country because of the six-month-long war. 

Until now, Iranian hackers had had only limited success in their cyberattacks against U.S. targets. In March, a hacktivist group called Handala disrupted the operations of medical tech giant Stryker. The U.S. government later accused Handala of being operated by Iran’s Ministry of Intelligence and Security (MOIS). Then, the group claimed responsibility for hacking the personal Gmail account of FBI director Kash Patel.

What effects have the attacks had?

The reality is that some systems inside critical infrastructure facilities are exposed to the internet and relatively easy to find. Earlier this month, cybersecurity firm Forescout reported finding more than 2,800 controllers in U.S. water systems exposed online. If a system is exposed, it doesn’t automatically mean hackers can take over control and cause real-world effects. But that has happened in some isolated cases in recent attacks.

The FBI said some of the cyberattacks around the country caused loss of pressure, which “could potentially allow untreated groundwater to seep into pipes,” and flooding. 

The town of Braham in Minnesota, one of the first ones to report an incident, had to take its water plant offline for a few hours, urging its around 1,700 residents to conserve water. The city of Maple Plain, also in Minnesota, briefly declared a state of emergency. In a county outside Atlanta, Georgia, local officials briefly told residents to boil water before using it as a precautionary measure.  

The worst effect, however, may be psychological. These attacks have been widely covered in national and local press, causing people to worry about the safety of a fundamental and basic need like water. That may very well be part of the hackers’ goals: to spread panic and fear.