Biggest US funding rounds, week ending 21st August

Updated August 2026. By Remy Beaumont.

Total raised in the US this week: $3.22bn across 10 disclosed rounds in the Crunchbase top ten.

Key takeaways

• Castelion raised $800m (plus $250m in debt) at a $13bn valuation for its hypersonic missile programme, led by JPMorgan Chase, Andreessen Horowitz, and Carlyle. Defence tech took the top spot for the first time since Hadrian's round three weeks ago.

• Etched raised $700m at a $21bn valuation for AI inference silicon, led by Jane Street. A quantitative trading firm leading a semiconductor round is a new capital formation pattern worth tracking.

• AI and defence accounted for roughly 85% of all capital deployed in the top ten this week.

• Total top-ten capital was down sharply from last week's $9.84bn, which was inflated by Databricks' $5bn raise. Excluding Databricks from the prior week, the run rate is comparable.

• Micromobility, health tech, and agentic finance each appeared in the top ten, signalling breadth beneath the AI and defence headlines.

What did the US funding week look like?

The week ending 21st August 2026 produced a concentrated pattern: defence tech at the top, AI infrastructure in three of the top five positions, and a visible absence of the multi-billion-dollar single-deal anomalies that characterised the prior two weeks. Without a Databricks or Thrive Holdings to skew the total, the week reveals what the US venture market looks like at its normal operating temperature. And at $3.22bn across ten disclosed rounds, that temperature is still historically elevated.

For the running picture of US funding across the month, see our monthly roundup of the biggest US funding rounds.

The most notable structural feature is the lead investor profile. JPMorgan Chase co-leading a defence tech equity round. Jane Street, a quantitative trading firm, leading a semiconductor deal. Disruptive, a specialist data infrastructure fund, leading Groq. The investor base for US venture has visibly expanded beyond traditional VC firms into finance houses, trading desks, and PE vehicles. For founders, this changes who should be on your target list. For observers, it changes how to read the signal embedded in a round's cap table.

Which was the biggest US round this week?

Castelion raised $800m in equity plus $250m in debt at a $13bn valuation, led by JPMorgan Chase, Andreessen Horowitz, and Carlyle. The Torrance, California-based company is developing a hypersonic strike missile.

The announcement mechanic deserves close attention. Castelion ran its round disclosure through Crunchbase's weekly top-ten roundup, not through a dedicated exclusive with a single outlet. No founder interview was visible in the first 48 hours. No CEO video on social media. No TechCrunch feature timed to an embargo lift. The round surfaced as a line item in a list, and the $800m equity figure, the $13bn valuation, and the JPMorgan name did the amplification work.

This is not the same as the Databricks "let the ARR speak" approach from last week. Castelion is pre-revenue at commercial scale; the product is a hypersonic missile in development. What spoke instead was the cap table: JPMorgan, a16z, and Carlyle together communicate institutional confidence to defence procurement decision-makers more effectively than any press placement could. The announcement strategy was the investor list itself.

For defence tech founders specifically, the JPMorgan co-lead is the detail to study. Traditional defence contractors are funded through a mix of government contracts and public markets. Castelion's private round structure, with a bulge-bracket bank co-leading equity alongside a top-tier VC and a PE firm, creates a new capital formation template for the sector. It signals that Wall Street sees hypersonic defence as a fundable thesis at private-market scale, not just a government procurement problem.

The other big rounds this week

Etched, $700m, San Jose, California. AI inference chip company Etched raised $700m in a round led by Jane Street, the quantitative trading firm, at a $21bn valuation. The investor list was notably long and prominent. Etched builds inference clusters designed to accelerate transformer-model computation. At four years old and $21bn, the valuation reflects the market's current pricing of AI silicon plays that sit between Nvidia's dominance and the startup layer.

The Jane Street lead is structurally interesting. Quantitative trading firms have deep expertise in low-latency computation, the exact domain Etched's inference hardware targets. Jane Street is not making a passive financial bet; it is investing in hardware that could reduce its own infrastructure costs. When a lead investor is also a potential customer, the signal is qualitatively different from a pure-play VC lead.

Higgsfield, $400m Series B, San Francisco. AI video and image creation platform Higgsfield closed $400m at a $5.4bn valuation, led by DST Global. At least 18 investors participated. The Series B label at $400m reflects how quickly AI content creation companies are scaling through funding stages. DST Global's lead continues its pattern of backing AI application-layer companies at growth stage.

Groq, $350m, San Francisco. Groq, which operates 13 data centres globally, raised $350m led by Disruptive, with planned participation from Nvidia. The $3.5bn valuation comes on the heels of a $650m round in June. Two rounds totalling $1bn in under three months signals an accelerated deployment phase, likely driven by customer demand for inference capacity that exceeds current buildout. The Nvidia participation in a company that competes at the inference layer is worth noting: Nvidia is hedging by investing across the inference stack, not just at its own GPU level.

Wispr Flow, $280m Series B, San Francisco. AI-powered voice-to-text tool Wispr Flow raised $280m at a $2bn valuation, led by Menlo Ventures. Voice interfaces for AI interaction are attracting growth-stage capital at a pace that was not visible six months ago. The $2bn valuation for a voice-to-text product reflects the market's bet that the input layer, how humans talk to AI systems, will be as valuable as the model layer.

Muon Space, $250m Series C, Mountain View, California. Satellite constellation designer and operator Muon Space raised $250m led by Eclipse. The company recently opened a manufacturing facility in San Jose capable of producing up to 500 satellites annually by 2027. Space hardware is now attracting defence-adjacent capital at growth stage, a pattern that mirrors the broader convergence of defence and dual-use technology funding.

Also, $150m Series D, Palo Alto. A Rivian spinout making electric bikes and small four-wheeled micromobility vehicles, Also raised $150m led by Prysm Capital. The Rivian lineage matters: corporate spinouts from well-known EV companies carry a credibility premium in micromobility, a sector that has historically struggled with unit economics at venture scale.

Where is US capital flowing?

Defence tech claimed the top position for the first time in this roundup series, with Castelion's $800m (plus $250m debt) representing roughly 25% of the week's total. AI inference and infrastructure (Etched, Groq, Velaura AI) accounted for approximately $920m or 29%. AI applications (Higgsfield, Wispr Flow) added $680m or 21%. Space and satellites (Muon Space) contributed $250m. Micromobility (Also) added $150m.

The defence-AI overlap is becoming harder to separate. Castelion's hypersonic missile programme involves AI-guided flight systems. Muon Space's satellite constellations serve dual-use intelligence purposes. The capital flowing into these companies is simultaneously funding AI infrastructure and national security capabilities.

The investor composition shift is the week's most durable signal. Of the ten rounds, at least three were led by non-traditional VC investors: JPMorgan (bank), Jane Street (trading firm), and Disruptive (specialist fund). This broadening of the US venture investor base has implications for how rounds are priced, structured, and announced.

Notable US launches this week

Castelion's debt-equity structure. The $800m equity plus $250m debt structure is unusual for a pre-commercial defence startup. The debt component suggests asset-backed financing against development contracts or government agreements, a structure more common in aerospace PE than in traditional venture.

Groq's back-to-back raises. Two rounds in under three months ($650m in June, $350m in August) totalling $1bn is a deployment signal, not a valuation signal. When a company raises twice in one quarter, it typically means customer demand has outpaced the prior round's planned use of proceeds.

Rillet reaches unicorn status. Rillet's $100m Series C at a $1bn valuation, its third financing in a year, makes it the latest agentic finance unicorn. The speed from Series A to unicorn status in under 18 months reflects how quickly the AI-for-enterprise-finance category is being priced.

What should founders raising soon do this week?

Expand your investor target list beyond traditional VCs. JPMorgan, Jane Street, and Disruptive leading rounds this week is not a one-off. Banks, trading firms, and specialist funds are actively competing for lead positions in US rounds. If your product has relevance to financial infrastructure, defence, or data, your investor list should include non-VC capital sources.

Study the Castelion cap table signal mechanic. If your company operates in a sector where the customer is also the regulator (defence, healthcare, energy), your investor names carry more weight than your press strategy. A cap table that signals institutional credibility to procurement decision-makers is doing marketing work that no exclusive can replicate.

Position inference hardware as a customer problem, not a technology pitch. Jane Street leading Etched is a customer-investor dynamic. If you can get a lead investor who will also be a user of your product, the valuation premium is substantial and the signal is qualitatively stronger.

Back-to-back raises are possible if demand supports them. Groq's two raises in three months show that the market will support rapid sequential fundraising when deployment demand is visible. If your last round's capital is being absorbed faster than planned, do not wait for the traditional 18-month cycle to raise again.

The rest of the week's top US rounds

Frequently asked questions

What was the biggest US funding round this week? Castelion raised $800m in equity plus $250m in debt at a $13bn valuation, led by JPMorgan Chase, Andreessen Horowitz, and Carlyle. The Torrance, California company is developing a hypersonic strike missile.

How much did US startups raise in total this week? $3.22bn across the top 10 disclosed rounds for the week ending 21st August 2026. This is down from last week's $9.84bn, which was dominated by Databricks' $5bn raise.

What stage attracted the most US funding this week? Growth-stage deals dominated. Castelion (Series C), Etched, Higgsfield (Series B), Groq, and Wispr Flow (Series B) all fall in the growth-to-late-stage range. Velaura AI was the notable Series A at $110m.

Who led the Castelion round? JPMorgan Chase, Andreessen Horowitz, and Carlyle co-led the $800m equity round. The JPMorgan co-lead is notable as one of the first major US bank-led defence tech venture rounds.

What was the announcement strategy behind the Castelion raise? Castelion did not place a dedicated exclusive or release a founder video. The round surfaced through Crunchbase's weekly roundup. The cap table, featuring JPMorgan, a16z, and Carlyle, functioned as the announcement's credibility engine, particularly for defence procurement audiences.

How do this week's US rounds compare to European deals? US funding in the top ten ($3.22bn) significantly exceeded European startup activity this week. The gap between US and EU deal sizes continues to widen at growth stage, though seed-stage activity in Europe remains competitive. For cross-market comparison, see our EU funding roundup for the same week.

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