[onlyrealcuzzo]

BlackRock buys stakes in investment firms that directly purchase real estate (some specifically SFH).

Those companies issue corporate debt (bonds) to buy houses.

The yield they need to offer goes down when the Fed manipulates bond prices by gobbling up non-corporate debt (US Treasuries & MBS).

BlackRock & other firms aren't taking on debt to invest in REITs - they're just directing more of their portofolio to REITs when The Fed drives down yields.