The following is a one-year chart of Berkshire Hathaway (B share).
As you can see, the stock did not move too much until this August, when the US sub prime loan started to fall out. It IS interesting to see investors jump back to the good old Berkshire during this uncertain time. Another notable event is Buffett sold all the PetroChina shares during this period, which brought in meaningful profit (investment gains) to Berkshire Inc.