Games Workshop Share Price Spike

I keep an eye on the GW share price - I may one day want to be a shareholder (especially if that means I get to vote on Board salaries!) and as a player and customer I have a vested interest in how well the company is performing. OVer Christmas though I had other things on my mind and didn't update the tracker on my tablet. When I did though, an amazing thing happened - the share price went from the low 400's to 530 in about a month. That's nearly a 25% jump. Here's a graph from the LSE to show what happened:



It happens around the 6th of January, the peak being hit around the 9th. So what prompted buyers to suddenly rush to buy GW stock?

I mentioned this to a few friends, some of whom have worked for Games Workshop, and they came up with two possible explanations; Christmas went well for most GW stores, who nearly all reported hitting their sales targets, or, the release of Vampire Counts could have been viewed as a positive step for the company.

Now don't get me wrong, I think some of the new VC models are very impressive, but not a 25% jump in share value impressive. Which left the sales figures, and them being leaked.

However, this week we saw the public release of some half-year financial figures from the GW group. Basically they are making mo' money - certainly good news for investors (in the short term at least, but that's another story), and possibly worth a bump in share price. But doesn't that mean the information was leaked ahead of time? Is that legal?

Addendum: It appears this is nothing new.

I winder if there is any way to find out who is buying all these shares?