Most-Active US Investors: Andreessen Horowitz Leads Slow Start To Spring

This is a monthly feature that runs down some of the most-active investors in U.S.-based companies, looks at some of their most interesting investments, and includes some odds and ends of who spent what. See February’s most-active startup investors here.

April did not bring a shower of startup funding deals, as venture investors seemed to retreat.

The numbers for the most-active startup investors in the U.S. certainly bear that out, as Andreessen Horowitz and Khosla Ventures were the only two firms to break double digits for deal count in April.

While it’s not unusual for those two firms to lead the pack, it is unusual for so many other big-name firms to spend a month on the sidelines. Regardless, let’s dive into the most-active U.S. startup investing firms last month.

Andreessen Horowitz, 13 deals

Topping this list is nothing new for Menlo Park, California-based VC giant Andreessen Horowitz. However, the baker’s dozen of deals is the most the firm has consummated in one month since January.

Per normal, not only did a16z participate in a lot of deals involving U.S.-based startups, it also went pretty big.

The firm co-led Base Power’s $200 million Series B along with Addition, Lightspeed Venture Partners and Valor Equity Partners. The Austin, Texas-based startup installs residential backup power systems — designed to charge batteries specifically when electric prices are low.

Andreessen Horowitz also led WeWork co-founder Adam Neumann’s residential real estate startup Flow’s $100 million-plus round at a $2.5 billion valuation, per a Bloomberg report. 

Khosla Ventures, 10 deals

Khosla also has been relatively active. The 10 deals it made last month marks the most for the firm since April 2024.

Khosla also led a pretty interesting deal, being the primary backer for Science’s $104 million round. The Alameda, California-based biotech is a Neuralink competitor — and was founded by a Neurolink co-founder — and is working on both a brain implant system and a retina implant to treat eye diseases. 

Khosla also participated in some large rounds, including data detection and response startup Cyberhaven’s $100 million Series D that valued it at $1 billion, and Mainspring Energy’s huge $258 million Series F. Mainspring builds generators, a business that has become appealing to investors as artificial intelligence continues to suck down energy.

General Catalyst, 9 deals

Speaking of that Mainspring Energy deal, the next firm on the list actually led it.

Unlike the previous two VC firms, General Catalyst actually slowed its pace of investment a little last month. The firm had taken part in 26 deals between February and March, but had its slowest month since January.

The Mainspring deal was by far the largest the firm took part in last month, but it also co-led much smaller deals for specialty insurance startup Vivere Partners and hydrogen energy firm Fourier.

Also notable:

• BoxGroup and Index Ventures came in next on the list with eight deals apiece.
• Ocampo Capital topped all firms for the most led or co-led deals last month with seven. Khosla and Andreessen Horowitz followed with five deals each that they led or co-led.
• Greenoaks Capital Partners led the list for rounds led or co-led with the highest dollar amounts, leading Safe Superintelligence’s massive $2 billion round at a $32 billion valuation.
• Y Combinator was the top investing incubator and accelerator once again, investing in 22 startups in April.

Methodology

This is a list of investors which took part in the most rounds involving U.S.-based startups. It does not include incubators or accelerators due to the fluctuations their investment numbers can have.

Illustration: Dom Guzman