This is kind of funny, but the explanation sounds logical.... https://www.huffingtonpost.com/dan-mirvish/the-hathaway-effect-how-a_b_830041.html "When Anne Hathaway makes headlines, the stock for Warren Buffett’s Berkshire-Hathaway goes up. Think of Berkshire-Hathaway shares (BRK.A) as a really expensive version of the IMDb’s StarMeter (which actually is designed to go up and down as actors make the news). But a bedrock member of the New York Stock Exchange? The evidence would indicate as much. Oct. 3, 2008 - Rachel Getting Married opens: BRK.A up .44% Jan. 5, 2009 - Bride Wars opens: BRK.A up 2.61% Feb. 8, 2010 - Valentine’s Day opens: BRK.A up 1.01% March 5, 2010 - Alice in Wonderland opens: BRK.A up .74% Nov. 24, 2010 - Love and Other Drugs opens: BRK.A up 1.62% Nov. 29, 2010 - Anne announced as co-host of the Oscars: BRK.A up .25% My guess is that all those automated, robotic trading programming are picking up the same chatter on the internet about “Hathaway” as the IMDb’s StarMeter, and they’re applying it to the stock market. "