This week in the world of startups, we saw a mixed bag of news, with some companies making headlines for all the wrong reasons, while others celebrated major milestones. From creative accounting scandals to nuclear reactor breakthroughs, here's a roundup of the most interesting startup stories from the past week.

One of the most notable stories this week was the revelation that 11x, a startup backed by a16z and Benchmark, had been using creative ways to calculate its annual recurring revenue. Sources close to the matter told TechCrunch that several companies listed on 11x's website were not actual customers, raising concerns about the startup's churn rate.

In other news, Cerebras Systems, an AI chipmaker, saw its IPO delayed again due to an ongoing national security review. The company had filed to go public in 2024, but the delay has left investors and analysts wondering when it will finally make its debut on the stock market.

On a more positive note, Terrestrial Energy, a U.S. nuclear startup, went public via SPAC and is expected to net $280 million. The company develops small modular reactors, a technology that could revolutionize the energy industry. Meanwhile, Bill Gates-backed Commonwealth Fusion Systems hit a key milestone in its quest to construct a demonstration reactor.

However, not all startups had a good week. Vertical farming company Plenty filed for bankruptcy after raising nearly $1 billion in funding from investors, including SoftBank Investment Advisers, Walmart, Bezos Expeditions, and Jeff Bezos as an angel investor. The company's demise has raised questions about the viability of vertical farming as a business model.

In other news, Block, the fintech startup co-founded by Jack Dorsey, laid off 931 people, according to a leaked email. The company, which owns Cash App and Square, had already conducted layoffs in 2024, and the latest round of job cuts has left many wondering about its future prospects.

Rumors were also swirling this week about potential acquisitions in the AI space. Nvidia is reportedly nearing a deal to acquire Lepton AI, a startup that rents out servers powered by its AI chips. Meanwhile, FuriosaAI, a South Korean startup that makes chips for AI applications, is said to have rejected an $800 million acquisition offer from Meta.

In the world of venture capital, digital banking startup Mercury raised $300 million in primary and secondary funding, more than doubling its valuation to $3.5 billion post-money. Island, a company that makes enterprise browsers, secured $250 million in a Series E led by Coatue, valuing the startup at $4.85 billion. Rivian spun out a new micromobility startup called Also, which received $105 million from Eclipse Ventures to build small EVs.

Other notable funding rounds included n8n, a Berlin-based workflow automation startup, which raised $60 million in a round led by Highland Europe. Mexico City-based YC alum Mendel raised a $35 million Series B, while Arcade, a generative AI marketplace, announced a $25 million Series A funding round and its expansion to home goods, starting with rugs.

Finally, Emergence Capital closed a $1 billion seventh fund to back B2B companies, with a keen interest in AI. French VC firm Daphni announced the first closing of its third fund, Daphni Blue, with around $215 million secured out of its overall $270 million target. Amazon's Alexa Fund also expanded its scope beyond voice startups, with a broader focus on AI investments.

As the startup ecosystem continues to evolve, one thing is clear: AI is playing an increasingly important role in the industry. A new report showcased the world's 20 hottest open source startups, with more than half of them having AI at their core. As we look to the future, it will be interesting to see how startups continue to innovate and push the boundaries of what is possible with AI.