DOJ's a16z probe puts a venture standard on trial: partners on boards of rival portfolio companies

The Justice Department has spent close to a year investigating whether Andreessen Horowitz's investment partners are improperly serving on the boards of competing artificial intelligence companies, according to people familiar with the matter cited by Fortune ^{[1] [2]}. What is exposed here is not one careless directorship but the standard venture template: a firm that takes a board seat with the check, installs a partner as director, and then does it again in an adjacent company ^[3].

The named pair is Databricks and Fivetran, both backed by the firm and both in the business of helping companies collect, organize and analyze large volumes of data ^{[4] [5]}. Co-founder Ben Horowitz sits on the Databricks board; partner Martin Casado sits on Fivetran's ^[6]. Casado was also a director of dbt Labs, which Fivetran acquired in June ^[7]. The DOJ reviewed that deal for months after its October announcement and cleared it unconditionally ^[8], having opened the interlock inquiry around the same time and kept it running after the deal closed ^[9]. Read plainly, the agency treated the merger and the board question as separate matters and let the second one live ^[10].

Section 8 of the Clayton Act, passed in 1914, bars a single person from sitting on the boards of two competing companies ^[11]. The wrinkle is that more than one individual director is at issue, so the firm itself is in the frame; the statute is worded to reach companies as well as individuals and a handful of courts have agreed, which still leaves a16z an avenue to contest any allegation ^[12].

The remedy history is unglamorous. Under Jonathan Kanter the DOJ pushed directors off boards rather than into court: Ari Emanuel left Live Nation's board in 2021 ^[13], and directors at more than 10 other companies exited in 2022 and 2023 ^[14]. Resolving these matters typically means someone resigns from one of the two boards ^[15]. That is cheap for a fund that wants information rights and expensive for one whose pitch is governance.

The scale explains the attention. Andreessen Horowitz managed $90 billion as of January and has raised a $15 billion fund, its largest, announced in January 2026 ^{[16] [17] [18]}, or roughly a sixth of assets under management ^[19]. Its limited partners include sovereign wealth funds, pension funds and university endowments ^[20]. Databricks is an IPO candidate in the portfolio, and Horowitz holds billions of dollars in potential returns from lead positions dating back to a $14 million round in 2013 ^{[21] [22]}.

Politics sits on top. Andreessen and Horowitz each donated millions in 2024 to a group aligned with then-candidate Donald Trump ^[23]; Horowitz later gave $2.5 million to a super PAC supporting Kamala Harris ^[24]; and Bloomberg News has reported that the firm successfully pushed the administration to remove many AI safety guardrails ^[25].

Watch three things. The DOJ has made no final decision and the matter could end with no action ^[26]; spokespeople for Databricks and the department declined to comment, and Andreessen Horowitz and Fivetran did not respond ^[27]. Accounts of how far along it is diverge: Fortune describes a nearly year-old inquiry, while a summary of Axios reporting says no charges, targets or timelines have emerged and the probe appears preliminary ^{[2] [28]}. And the real signal will not be a court filing but a quiet director departure at Databricks or Fivetran, followed by term sheets elsewhere that convert board seats into observer rights.