Shares of AMC Entertainment Holdings Inc. /zigman2/quotes/200235402/composite AMC +0.25% dropped 1.9% in premarket trading Thursday, after the movie theater operator filed for the sale of up to 200.0 million Class A shares. Based on Wednesday's stock closing price of $4.32, the offering could be worth up to $864 million, which compares with AMC's market capitalization of $593.5 million. AMC said it may sell the shares from time to time, in one or more series or issuances, and on terms that will be determined at the time of the offering. The company said it had 85.6 million Class A shares and 51.8 million Class B shares outstanding as of Oct. 30. The stock has dropped 34.6% over the past three months through Wednesday, while the S&P 500 /zigman2/quotes/210599714/realtime SPX +1.95% has gained 6.2%.