Hi Filippo,
I would not recommend to take a closer look at historical prices .. unless you also add a remark that the BitAsset 2.0 scheme will be much different.
Actually, the bitAsset 1.0 (which is currently traded in BitShares) did not closely follow the USD .. mainly, so I assume, because of lack of participants in the decentralized exchange due to the heavy User interface.
Do you have a deadline for your thesis? Maybe you could compare bitasset 1.0 with bitassets 2.0 and show the differences between both .. in particular in regards to stability.