In good times, the “Warren Buffett effect” has caused Apple shares to soar — by showing everyone that the world’s most famous investor believes in Apple. However, the opposite is also true: An apparent second thought on the part of Buffett’s firm Berkshire Hathaway can cause shares to fall.
That’s what happened this week, when Berkshire Hathaway was revealed to have slightly reduced its Apple holdings. Responding to the news, Apple shares fell 0.5 percent in pre-market trading.