The graph of yew logs seem to show that the item has peaked. The inflection point at 571 GP already predicted a fall in the nearby future.... I'm guessing it is now.
Like Red Chins, they are probably not rising again this week.
Will even out at the their approximate value at the time of the xp weekend's announcement, as by that point solo merchers will begin to buy the logs in the hope of making a quick buck.
I have a feeling that all the items, including yew logs will rise again a few days before or during the double xp weekend. People simply bought out and merched for what was there, now people the people that are going to buy are the people that are going to use the supplies.
Currently they are on the decline. Right now they are worth 514gp, a few days ago they were as high as 580s. How high do you think they will get for the Double XP weekend