A proxy advisor has sued Oklahoma over House Bill (HB) 4429, creating the latest test of whether states can continue pursuing restrictions on proxy voting advice after a string of courtroom defeats for similar measures. The challenge arrives as policymakers seek ways to maintain pressure on proxy advisors despite continued judicial scepticism toward state-led regulation.

The lawsuit matters beyond Oklahoma. Together with recent cases in Kansas, Indiana and Texas, it will help determine whether states can craft legally sustainable restrictions on proxy advisory services or whether courts will continue to view such measures as unconstitutional interference with independent analysis.

Oklahoma becomes the latest proxy advisor battleground

Oklahoma's HB 4429 was signed into law in May and is scheduled to take effect on 1 November. The legislation forms part of a broader campaign by Republican-led policymakers to increase scrutiny of proxy advisors, particularly where voting recommendations diverge from management positions.

The proxy advisor challenging the law argues that HB 4429 unlawfully restricts its ability to provide independent corporate governance research and recommendations. According to the complaint, the measure would distort the information available to institutional investors by imposing additional obligations only when proxy advice conflicts with management's preferred outcome. The firm branded the legislation as "yet another law designed to impose onerous obligations on proxy advisors when, and only when, our independent guidance does not align with corporate management".

What could make the Oklahoma case particularly important is whether HB 4429 can be distinguished from earlier state laws that have already struggled in federal court. Supporters of proxy advisor regulation have repeatedly argued that new measures are better tailored than their predecessors, while opponents contend they still amount to viewpoint-based restrictions on independent research. The Oklahoma litigation may therefore provide an early indication of whether lawmakers have found a more durable legal approach or are repeating arguments that courts have already rejected.

Federal scrutiny of proxy advisors intensifies

The lawsuit also comes amid renewed federal attention on the proxy advisory industry.

Earlier this month, the US Department of Justice's Antitrust Division withdrew a letter that had effectively recognised the legality of proxy advisory services for almost four decades. In announcing the decision, the Department cited concerns regarding competition and market structure within the sector.

Those concerns echo themes raised in President Donald Trump's Executive Order 14366, signed in December, which directed the Securities and Exchange Commission to review its proxy advisor rules and instructed the Attorney General and Federal Trade Commission to examine potential antitrust and consumer protection concerns involving proxy advisors. Publicly visible progress under the order has so far been limited, but the withdrawal of the DOJ letter suggests scrutiny of the industry remains active. While the federal developments are separate from Oklahoma's statute, they reinforce a broader political effort to challenge the role of proxy advisors through multiple regulatory and legal channels.

Not all observers agree with that approach. ValueEdge Advisors criticised the DOJ's decision, arguing that there is no clear evidence of antitrust violations and that the move sits uneasily alongside traditional Republican support for free markets and limited government intervention.

Courts remain a significant obstacle

The Oklahoma case arrives against a backdrop of repeated legal setbacks for state-level restrictions. Federal judges have recently blocked both Kansas' Proxy Advisory Transparency Act and Indiana's HB 1273, while Texas' SB 2337 faced a preliminary injunction last year.

These rulings matter because they suggest courts are prepared to look beyond lawmakers' stated objectives and examine whether the practical effect of such laws is to disadvantage proxy advice that differs from management's position. The constitutional concerns raised in the earlier cases may also feature prominently in the Oklahoma litigation, depending on how courts interpret HB 4429's specific requirements.

Policymakers explore new avenues

At the same time, efforts to challenge proxy advisors are increasingly extending beyond state legislation.

Last month, 18 Republican members of the Texas congressional delegation requested updates from the Federal Trade Commission and the Acting US Attorney General regarding investigations launched under Executive Order 14366. The intervention reflected concerns among supporters that progress had been limited since the order was issued.

Commenting when the letter was sent, Sarah Wilson, CEO of Minerva Analytics, said "that progress against proxy advisors has been slow is not all that surprising; the legal theories the Executive Order directed the agencies to test have fared badly in court".

Texas has also begun pursuing a different legal strategy. Rather than relying primarily on SB 2337, which has faced significant constitutional challenges, Texas Attorney General Ken Paxton recently launched a new lawsuit against a major proxy advisor under the Texas Deceptive Trade Practices Act. The case alleges that the firm misled clients regarding the basis of its voting recommendations.

This development follows earlier actions by Texas and similar initiatives in Florida, Iowa, Missouri, Nebraska and West Virginia. Taken together, they suggest political pressure on proxy advisors is adapting rather than disappearing as legislative approaches encounter resistance in court.

What HB 4429 Means for Proxy Advisor Regulation‍

The most important question may not be whether Oklahoma prevails, but whether HB 4429 demonstrates a regulatory formula capable of surviving judicial scrutiny. If it fails alongside similar laws in Kansas, Indiana and Texas, policymakers may increasingly shift their efforts from legislation toward antitrust, consumer protection and other legal avenues.