[grimoire]

He used 6 dates:

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%

I'm not a statistician, but 6 dates could hardly be considered a correlation. I would also think that no Anne Hathaway news should result in no positive price changes for a correlation to exist.

Seems like the article confuses correlation with "funny coincidence".

And it certainly doesn't "drive" the stock, as the headline states. That implies a causation, which is even stronger than a correlation.

[akronim]

I would also think that no Anne Hathaway news should result in no positive price changes for a correlation to exist

That's not correct. Imagine the stock price can be derived from two factors A and B such that price = A + B. A is correlated with the price, but a positive price change could also happen caused by B. So no change in A does not guarantee no change in price. And in the case of BRK.A there would be many such factors.

[jfoutz]

well, if you look at the chart, BRK.A has been climbing that whole time. someone less lazy than me could count up how many days it went up, and how many days it went down and give you a a good number. let's just say there are 100 down days, and 200 up days.

what are the chances of selecting 6 up days without replacement? 200/300 * 199/299 * 198/298 * 197/297 * 196/296 * 195/295 ~ 0.085

(i'm also not a statistician, and i'm not real sure i did that right.)

[joshu]

Historically picking dates isn't something you would actually be able to do. Article is poorly reasearched.

(I use to do this professionally.)