I went to the "source" slideshow, and I still can't tell how much these categories overlap. Part of my 401K is invested in a strictly-U.S. Treasury Bonds mutua

I went to the "source" slideshow, and I still can't tell how much these categories overlap. Part of my 401K is invested in a strictly-U.S. Treasury Bonds mutual fund. Does that count as owned by a household or by a mutual fund or get counted twice? [Edit: I didn't read far enough in the source: the linked article misstated "Federal Reserve" as "Treasury"] Also, how does the U.S. Treasury "own" the debt? I thought Treasury issued the debt, and the Federal reserve controlled (more exactly "influenced") the interest rate by deciding how much of those bonds to buy. So I expected the Federal Reserve should have shown up as a large debt holder.