It means "up to the present moment". It means that something, until this moment, is in a way, but it could change in the future. "What are the best films of 2017 so far?" "In spite of the leak, Sunday's Game of Thrones was the most-watched episode so far"

"So far" at the end of a sentence qualifies or hedges an assertion. You can use it when things may change for better or worse, or in some other respect. As in, "the organization is in good financial shape so far." The speaker may or may not have a particular loss or gain in view as likely. If not, he is just expressing his own cautiousness. After all, things always do change.