US Startup Funding Rounds: September 14, 2026 – September 20, 2026
25 US venture rounds closed between September 14, 2026 and September 20, 2026, led by Arcee AI at $1B (Series B).
Every round below is a named venture round by a US-headquartered company, sourced from SEC filings and verified announcements. Investment funds, IPOs, post-IPO placements and valuation-only reports are excluded.
| Company | Location | Amount | Round | Date | What they do |
|---|---|---|---|---|---|
| Arcee AI | Miami, Florida | $1B | Series B | September 16, 2026 | Arcee AI is a company specializing in domain-specific models and tools for enterprises to create their own efficient and customizable small language m… |
| Angle Health | San Francisco, California | $600M | Series C | September 18, 2026 | Angle Health democratizes access to modern healthcare services by unifying today's fragmented healthcare benefits ecosystem into one core coverage and… |
| Impulse Space | Redondo Beach, California | $308M | Series D | September 16, 2026 | Impulse Space, the in-space transportation company founded by Tom Mueller, is opening access beyond Low Earth Orbit (LEO) with its fleet of in-space t… |
| Arsi AI | Banten | $150M | Series B | September 17, 2026 | Arsi AI is a U.S. startup that develops open-weight AI models, giving companies greater control over the AI systems they use. The company's flagship m… |
| Mazama Energy | Bend, Oregon | $135M | Series B | September 18, 2026 | Mazama Energy is a geothermal operator and development company dedicated to advancing technologies and methods for extracting heat from superhot rocks… |
| Sling Therapeutics | Ann Arbor | $123M | Series C | September 16, 2026 | The company is also exploring additional potential indications beyond TED, including in rare and autoimmune diseases. The company is advancing the eva… |
| Circle Pharma | South San Francisco, California | $92.5M | Series E | September 16, 2026 | Circle Pharma is a biotechnology company creating bioavailable macrocyclic peptide therapeutics that target protein-protein interactions. |
| Wealth.com | Phoenix | $65M | Series B | September 14, 2026 | wealth.com is the industry’s leading estate planning platform, empowering 500+ wealth management firms to modernize the delivery of estate planning gu… |
| Nuance Labs | Seattle, Washington | $50M | Series A | September 14, 2026 | Nuance Labs is a Seattle-based AI research lab founded by former Apple PhD researchers developing a full-duplex foundation model for human conversatio… |
| Raindrop | San Francisco, California | $50M | Series A | September 17, 2026 | Raindrop is a monitoring platform designed specifically for AI agents. It addresses the complexities of AI agent failures by providing customized moni… |
| Daytona | New York, New York | $48M | Series B | September 17, 2026 | Daytona provides a secure, scalable infrastructure for executing AI-generated code. Our platform delivers instant environment creation, complete isola… |
| Luzern Risk | New York, New York | $45M | Series B | September 17, 2026 | Luzern Risk is the first captive insurance platform purpose-built for the mid-market. Combining decades of insurance expertise with modern technology,… |
| BackOps.ai | San Francisco, California | $42M | Series B | September 16, 2026 | BackOps.ai is a provider of an AI-driven platform designed to automate supply chain logistics. The company enables supply chain customers to integrate… |
| Noetive | San Francisco, California | $41M | Seed | September 16, 2026 | Noetive is an AI NeoLab that specializes in operational technology, aiming to build the intelligence of record for the physical economy. It focuses on… |
| Artificial Intelligence Underwriting Company | San Francisco, California | $40M | Series A | September 15, 2026 | The Artificial Intelligence Underwriting Company (AIUC) focuses on providing insurance coverage and rigorous safety standards to help enterprises depl… |
| TypeSafe AI | San Francisco, California | $40M | Seed | September 15, 2026 | TypeSafe AI is a frontier AI lab focused on building machine-native, composable AI. Founded by former OpenAI researcher Diogo Almeida and his team, th… |
| Rune | London, Virginia | $40M | Series A | September 16, 2026 | Rune is a defense tech startup that develops software to help the military manage field logistics more efficiently. Founded by former employees of And… |
| ReEmerge | Minnesota | $37M | Series A | September 15, 2026 | ReEmerge, Inc. is a private MedTech company that focuses on innovating new ways to address cognitive impairments, particularly caused by traumatic bra… |
| Comp AI | San Francisco, California | $34M | Series A | September 17, 2026 | Comp AI is an emerging player in the compliance automation space, focused on transforming how companies achieve compliance with critical frameworks li… |
| Branch Energy | Houston | $33M | Series B | September 15, 2026 | Branch Energy is a technology company that makes it easy for consumers to lower their energy bills and carbon footprint while providing dramatically b… |
| Hanover Park | New York, New York | $27M | Series A | September 17, 2026 | Hanover Park is a NYC-based provider of an AI-native fund administrator service for private equity and venture capital. The company is developing a pl… |
| Composio | San Francisco, California | $25M | Series A | September 14, 2026 | Composio provides the learning infrastructure that enables AI agents to improve through experience. By creating a shared skill layer that captures and… |
| Footprint | Gilbert, Arizona | $25M | Series B | September 16, 2026 | Footprint is a global materials science and technology company with a clear vision to create a healthier planet and healthier people. Our mission is t… |
| Atolio | San Francisco, California | $24M | Series A | September 14, 2026 | Atolio is the way enterprises safely and securely deploy enterprise search across siloes of information. Founded in 2019, the mission of Atolio is to … |
| Kastle | Falls Church, Virginia | $24M | Series A | September 17, 2026 | — |
Frequently asked
Which US startups raised funding between September 14, 2026 and September 20, 2026?
25 US companies closed named venture rounds between September 14, 2026 and September 20, 2026, raising $3.10B in total. The largest were Arcee AI ($1B, Series B), Angle Health ($600M, Series C), Impulse Space ($308M, Series D). Each round below is sourced from SEC filings and verified announcements, and excludes investment funds, IPOs and post-IPO placements.
What was the largest funding round of the week of September 14, 2026?
Arcee AI of Miami, Florida raised $1B in a Series B round announced September 16, 2026. Arcee AI is a company specializing in domain-specific models and tools for enterprises to create their own efficient and customizable small language models (SLM It was the largest US venture round recorded in this window across 25 qualifying rounds.
How many US venture rounds closed this week?
25 named US venture rounds closed between September 14, 2026 and September 20, 2026, totalling $3.10B. This counts only rounds with a named series (Seed through Series G+) by US-headquartered operating companies. Investment funds raising vehicles, IPOs, post-IPO equity and valuation-only reports are excluded so the figures reflect genuine startup fundraising.
These are the rounds. Fundz gives you the people to call at each one — verified decision-makers matched to your market, the moment a round lands.
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