I’m new to Bitcoin and would like to do some research for a data science project.
I am focusing on the visualization of some transaction chains that allow users to visualize them with color schemes or pictograms.
I gather that in 2013 so-called mixers began to arise that allow different users to function as different inputs of the transaction.
My question is: before 2013, can we assume that all the various inputs in every transaction belonged to a single user?
If not, would it have been the same in 2010 or 2009?