NEW YORK (

TheStreet

) --

Best Buy

(BBY) - Get Report

was the worst-performing stock in the

S&P 500

on Thursday.

The S&P 500 was rising 10 points, or 0.76%, intraday Thursday to 1,325.

Shares of Best Buy fell 7.54% to $18.39. Best Buy founder and Chairman Richard Schulze resigned from the company's board Thursday. Schulze previously planned on leaving his position as chairman on June 21 following Best Buy's 2012 annual meeting.

Best Buy conducted an independent investigation following allegations about the personal conduct of former CEO Brian Dunn. Dunn resigned in April. When the investigation's results were released on May 14, it found that Schulze failed to tell the board's audit committee about what he knew of Dunn's actions in December 2011.

"In December, when the conduct of our then-CEO was brought to my attention, I confronted him with the allegations (which he denied), told him his conduct was totally unacceptable and contrary to Best Buy's policies and everything I, and the Company, stand for. I understand and accept the findings of the Audit Committee," Schulze said in a statement.

On May 12, Hatim Tyabji was elected to succeed Schulze as chairman following the annual meeting. Tyabji was chairman of the company's audit committee.

Best Buy trades at an estimated price-to-earnings ratio for next year of 4.75 times; the average for its peers is 5.72.

Twenty-two of the 29 analysts who cover Best Buy rated it hold. Four analysts gave the stock a buy rating and three rated it sell.

The stock has declined 21.35% year to date.

-- Written by Alexandra Zendrian

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