Why JPMorgan Chase earnings came out early

JP Morgan Chase
Adam Jeffery | CNBC

JPMorgan Chase surprised Wall Street when the bank's third-quarter earnings report appeared very early on Tuesday, several hours sooner than expected.

"At approximately 3.36 AM EST, Shareholder.com inadvertently made a supplemental earnings file from JP Morgan Chase's third-quarter earnings announcement publicly accessible," Nasdaq said in a statement. "The root cause was a human error internally at Shareholder.com. The issue was contained only to JPMorgan Chase and did not impact any other Shareholder.com clients."

In 2006, Nasdaq acquired Shareholder.com, which specializes in shareholder communication and investor relations intelligence services.

JPMorgan later confirmed the leaked document, with the biggest U.S. bank posting earnings of $1.36 a share on revenue of $25.1 billion.

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Citigroup and Wells Fargo also reported quarterly results before the bell on Tuesday.