The Justice Department is examining whether Andreessen Horowitz's board seats at Databricks and Fivetran violate Section 8 of the Clayton Act — a rarely-used 1914 anti-interlock provision aimed, this time, at venture capital.

For nearly a year, the Justice Department has been quietly asking whether two Andreessen Horowitz partners are breaking a 1914 antitrust law by sitting on the boards of companies that now compete, Bloomberg reported (external source, opens in a new tab) Monday. The seats: co-founder Ben Horowitz at Databricks, valued at roughly $190 billion, and partner Martin Casado at Fivetran. The legal hook is Section 8 of the Clayton Act, which bars one person from directing two competitors — an "interlock."

Why the industry is baffled: when a16z first backed both, they weren't rivals. Each helped businesses move and organize large volumes of data, in different lanes. That changed. Databricks extended its Lakeflow product into the AI data pipelines and connectors that are Fivetran's home turf, and Fivetran itself got bigger — merging in an all-stock deal with dbt Labs (external source, opens in a new tab), another a16z portfolio company. That merger closed June 1, and the combined business now says it serves more than 100,000 data teams. The result: a16z sits on both sides of a data-infrastructure market its own checks helped consolidate.

That is the cap-table fact the "nobody could have foreseen this" framing glosses over. A board member sees roadmaps and pricing an ordinary shareholder never does. The textbook remedy for an interlock is giving up a seat — but since two separate partners hold these two, a16z could instead argue for a wall between Horowitz and Casado. Nothing has been decided.

The open questions are the ones that matter: whether the DOJ forces a divestiture, whether it treats a firm-held seat as a single "person" under the statute, and whether it acts at all. Section 8 has almost never been pointed at venture capital, which is exactly why the industry is watching this one. Andreessen Horowitz, Databricks, and the DOJ declined to comment.