It's not, obviously. He's digging through the Trump family financial records, and per the report I linked above, even now digging through records at the RNC. The goal is to impeach Trump. If that fails, gather as much opposition research as possible to take him down in the next election. All paid for with tax dollars.
I'm referring to factual, verifiable information about Mueller's work. That involves several indictments at this point in time.
It's interesting that the report you cited references an article from Forbes magazine about Jared Kushner's role in the Trump campaign. I pegged that article as 100% B.S. when it was posted here months ago by Freepers who claimed that it was evidence of Kushner's exceptional political genius.