Praise

Former Federal Reserve Chairman Alan Greenspan praised the Sarbanes–Oxley Act in 2005: "I am surprised that the Sarbanes–Oxley Act, so rapidly developed and enacted, has functioned as well as it has ... the act importantly reinforced the principle that shareholders own our corporations and that corporate managers should be working on behalf of shareholders to allocate business resources to their optimum use".

SOX has been praised by a cross-section of financial industry experts, citing improved investor confidence and more accurate, reliable financial statements. The CEO and CFO are now required to unequivocally take ownership for their financial statements under Section 302, which was not the case prior to SOX. Further, auditor conflicts of interest have been addressed, by prohibiting auditors from also having lucrative consulting agreements with the firms they audit under Section 201. SEC Chairman Christopher Cox stated in 2007: "Sarbanes–Oxley helped restore trust in U.S. markets by increasing accountability, speeding up reporting, and making audits more independent".

The Financial Executives International (FEI) 2007 study and research by the Institute of Internal Auditors (IIA) also indicate SOX has improved investor confidence in financial reporting, a primary objective of the legislation. The IIA study also indicated improvements in board, audit committee, and senior management engagement in financial reporting and improvements in financial controls.

Financial restatements increased significantly in the wake of the SOX legislation, as companies "cleaned up" their books. Glass, Lewis & Co. LLC is a San Francisco-based firm that tracks the volume of do-overs by public companies. Its March 2006 report, "Getting It Wrong the First Time," shows 1,295 restatements of financial earnings in 2005 for companies listed on U.S. securities markets, almost twice the number for 2004. "That's about one restatement for every 12 public companies-up from one for every 23 in 2004," says the report.

A fraud documented by the Securities and Exchange Commission (SEC) in November 2009, validated whistleblower allegations first logged in 2005.  may be directly credited to Sarbanes-Oxley. The fraud, which spanned nearly 20 years and involved over $24 million, was committed by Value Line (Nasdaq: VALU) against its mutual fund shareholders. The fraud was first reported to the SEC in 2004 by the then Value Line Fund (Nasdaq: VLIFX) portfolio manager and Chief Quantitative Strategist, Mr. John (Jack) R. Dempsey of Easton, Connecticut, who was required to sign a Code of Business Ethics as part of SOX. Restitution totaling $34 million was placed in a fair fund and returned to the affected Value Line mutual fund investors. The Commission ordered Value Line to pay a total of $43,705,765 in disgorgement, prejudgment interest and civil penalty, and ordered Buttner, CEO and Henigson, COO to pay civil penalties of $1,000,000 and $250,000, respectively. The Commission further imposed officer and director bars and broker-dealer, investment adviser, and investment company associational bars ("Associational Bars") against Buttner and Henigson. No criminal charges were filed.

The Sarbanes–Oxley Act has been praised for nurturing an ethical culture as it forces top management to be transparent and employees to be responsible for their acts whilst protecting whistleblowers. Indeed, courts have held that top management may be in violation of its obligation to assess and disclose material weaknesses in its internal control over financial reporting when it ignores an employee's concerns that could impact the company's SEC filings.