The US DoJ is considering joining Texas’ antitrust case against BlackRock (BLK) and State Street (STT)

The underlying theory here, that large common owners of competing firms can soften competition, has circulated in academic and enforcement circles for years without yet producing a decisive court outcome, so the case sits at the untested end of antitrust doctrine. That matters for the sequence: comparable actions against index providers and asset managers have historically played out over years through motions to dismiss, discovery, and possible settlement, with headline risk concentrated at procedural milestones rather than continuous repricing. The channel to equity value runs through potential remedies, constraints on stewardship or index concentration, rather than through near-term earnings, since passive fee economics are unaffected by litigation alone. Worth watching is whether DoJ formally files, which other states attach, and whether the remedy language targets voting and engagement practices rather than structure, as that distinction separates an operational nuisance from a business-model challenge. The peer read-across is to the other large index franchises named or implied by the same ownership logic.