How much is Mark Hurd worth?

Dennis Berman reports that:

Oracle investors, who were cheered by the hiring of H-P’s former top boss ...pushed Oracle shares up 5.76%, on a day when the overall market was down about 1%.

The increase is an astounding one, given Oracle’s size. It already had a market capitalization of around $115.2 billion. If you believe that the stock move was directly tied to Hurd, that means his hiring was worth about $6.76 billion overall.

That means that Hurd is himself worth more than the value of Harley-Davidson, Inc. ($6.24 billion); Whole Foods Market Inc ($6.13 billion) or Tiffany & Co. ($5.13 billion).

Did Mark Hurd really add almost $7 billion in value to Oracle? Before you answer that, consider that "HP saw $10 billion briefly wiped off its stockmarket value" when Hurd left it.

As I see it, there are several possible explanations:

1. The stock markets are semi-strong form efficient, so Mark Hurd's intrinsic value really is something between $7 and $10 billion.
2. The markets are semi-strong form efficient, but only in a relative sense, so all this tells us is that the news of Hurd's firing and hiring was valued on average by investors at something between $7 and $10 billion.
3. The markets are semi-strong form efficient, but something else must have happened on the relevant dates that acts as a confounding factor. Further study is warranted.
4. The markets are semi-strong form efficient in the long run, but are also subject to systematic biases triggered by irrational investor actions, such as herd behavior. The people who sold HP and bought Oracle are lemmings. You get enough lemmings going in one direction and investor sentiment no longer comes out in the wash (to mix metaphors). The market will adjust soon enough.
5. The stock markets are not semi-strong efficient. Behavioral finance proves it. This is just more evidence for the proposition.
6. The stocks markets are a rigged casino run for the benefit of powerful, dark forces.

Personally, I'd go with # 4.