Coldone and his army went on a buying spree from what I'm reading. This coldone guy says he's going to put a plan in action, he calls up his army and the next thing you know, Yahoo is up 5% or more. I've watched him do it at least 5 times over the last few months.
In terms of the immediate reason it is Yahoo Japan, in terms of the trend it is Alibaba's growth and the clock ticking towards an eventual IPO.
I expected the IPO to be announced just after the new year, now I see it as happening at any time, but I hope that Alibaba and Yahoo will work together to maximize Yahoo's tax position and a long term partnership between the two companies. While Alibaba's owners probably would rather have been able to buy out Yahoo's interest a long time ago, they understand that yahoo's investment (along with that of Softbank) provided the funds that jump started Alibaba's growth. If Alibaba decides on IPOing in a NY exchange, the long term relationship with Yahoo might help the global community understand the legitimacy of the company. I don't think it really matters as much if they IPO in Hong Kong.
Regardless, I am expecting Yahoo to move up significantly when the IPO is announced.....
I see no reason not to expect Yhoo to top 50 with an announcement of the IPO.....until then it will float and bob on rumors and minor news. I will continue to buy more on drops. If others are thinking like me I think the trading seen over the past 3 months is the pattern you will continue to see until a firm IPO announcement or a robust rumor of it moves carries the value up to what I think is yhoo's real value.