Halliburton Co. v. Erica P. John Fund, Inc.
The Court kept in place its 1988 rule letting defrauded stock investors sue as a group without each one proving they personally heard and relied on a company's lie, reasoning that an efficient stock market already builds public statements into the price everyone pays.
But the Court also ruled that companies accused of fraud must get a chance, before a lawsuit is certified as a class action, to show with direct evidence that the alleged lie never actually moved the stock's price -- and if it didn't, the whole basis for a group lawsuit disappears.
“Before overturning a long-settled precedent, however, we require "special justification," not just an argument that the precedent was wrongly decided.”
The Court explains the high bar for overturning its earlier Basic decision.
How it got here: A federal trial court and the Fifth Circuit denied class certification; the Supreme Court vacated once already in 2011, and on remand the lower courts again ruled for the investors, prompting Halliburton's second trip to the Supreme Court.
The Case in Depth
What happened
Investors in Halliburton stock sued the company and an executive, claiming Halliburton lied about its asbestos liabilities, expected revenue from certain contracts, and the benefits of a merger, all to keep its stock price inflated. When Halliburton later corrected these statements, the stock price dropped and investors say they lost money. The investors sought to sue as a single class covering everyone who bought Halliburton stock during the relevant period.
The question before the Court
When shareholders sue a company for lying about its business and try to sue as a group, can the company fight back before the lawsuit is even certified as a class action by showing its statements never actually moved the stock price?
The Court's answer
Partly. The Court refused to overrule or narrow its 1988 rule letting defrauded stock investors sue as a group by presuming they relied on a company's public misstatements, since an efficient market already builds those statements into the price everyone pays. Halliburton had argued that shaky economic theory and newer class-certification cases required scrapping that presumption, but the Court found no "special justification" strong enough to abandon a quarter-century-old precedent.
At the same time, the Court sided with Halliburton on its narrower request: companies must get to introduce direct evidence, before a class is even certified, that an alleged lie never actually moved the stock's price. If a company can show that, the entire basis for treating the case as a group lawsuit collapses, so fairness requires letting defendants make that showing early rather than waiting for trial.
Curious how the Court got there? See the step-by-step legal reasoning →
Why it matters
Companies facing shareholder class actions gain an earlier, more powerful tool to knock out weak suits before the expensive class-certification stage, potentially avoiding settlement pressure tied to certification. Shareholders retain the ability to sue as a group without proving individual reliance, but only if the company can't show its statements had no real effect on the stock price.
What changes now
The case returns to the lower courts, which must now let Halliburton present its evidence that its alleged misstatements did not actually affect its stock price before deciding whether to certify the investor class. If Halliburton succeeds, the presumption of reliance falls apart and the case cannot proceed as a class action without individualized proof of reliance from each investor. The ruling is a final merits decision, not a temporary order, and will shape how securities class actions are litigated nationwide.
What this does not decide
The Court did not decide whether Halliburton's statements actually lacked price impact -- that factual question goes back to the lower courts. It also left untouched the four existing prerequisites for invoking the presumption of reliance, declining Halliburton's separate request to require plaintiffs to prove price impact directly just to invoke the presumption in the first place.
Concurrences and dissents
Concurrence — Justice Ginsburg
Justice Ginsburg joined the Court's opinion but wrote separately to stress that it is the defendant's burden to prove the absence of price impact, not the plaintiff's burden to prove its presence. She emphasized this placement of the burden should mean the ruling imposes no heavy new cost on shareholders with legitimate fraud claims.
Concurrence — Justice Thomas
Justice Thomas agreed only with the outcome, not the reasoning, and argued the Court should have overruled Basic entirely. He contended Basic's presumption rested on outdated economic assumptions about market efficiency and investor behavior, conflicts with the Court's later class-certification cases requiring actual proof of predominance, and is so hard to rebut in practice that it has erased the reliance requirement altogether.
How the Court got there
The legal reasoning, step by step
- The Court applied stare decisis, the principle that long-settled precedents should stand absent a 'special justification' beyond simply believing the earlier case was wrong, to evaluate Halliburton's request to overrule the 1988 Basic decision.
- Basic had adopted the 'fraud-on-the-market' theory, which holds that in an efficient market a stock's price already reflects public information, so anyone who buys or sells at that price can be presumed to have relied on any public lies baked into it, without needing to show they personally heard the statement.
- The Court rejected Halliburton's economic critique of market efficiency, explaining that the presumption rests only on the modest premise that public information generally affects prices to some degree -- not on a rigid, all-or-nothing view of efficiency -- so ongoing academic debate about degrees of efficiency did not undermine that modest premise.
- The Court also rejected the argument that the presumption is incompatible with Rule 23's requirement that plaintiffs actually prove class-certification requirements, explaining that plaintiffs still must prove the presumption's building blocks -- public disclosure, materiality, market efficiency, and timing -- before certification, rather than simply presuming predominance.
- The Court then reasoned that because the presumption's entire logic depends on the challenged statement actually having moved the stock's price ('price impact'), and because that fact is available through direct evidence rather than only indirect proxies, fairness and consistency with Rule 23 require letting defendants introduce that direct evidence to rebut the presumption before certification, not just at a later merits trial.
- Applying this to Halliburton's case, because the lower courts had refused to let Halliburton use its price-impact evidence at the certification stage, the Court concluded Halliburton had been wrongly denied a chance to defeat the presumption early in the case.
Doctrinal impact
Cases affected by this decision
Reaffirms Basic Inc. v. Levinson (485 U.S. 224)
The Court declined to overrule Basic, keeping its presumption that investors rely on a company's public misstatements.
Distinguishes Amgen Inc. v. Connecticut Retirement Plans and Trust Funds
The Court distinguished materiality (left for trial) from price impact, which must be addressed before class certification.