Eregulla Deeps, page-261

No, the SF is highly unlikely to know who the predator/short seller is. The typical SF lender is the passive manager position, the index fund. This is your garden variety equity fund where buys and sells are computer driven with no insight, and the benchmark is track the index. Index goes up, fund goes up, index goes down, fund goes down. There is no penalty on the manager if the index falls so the manager has no care as to the SP movement of stock lent.

It gets more complex for the bigger funds, they have multiple equity mandates operating simultaneously, a passive manager and an active manager, even a leftfield active manager chasing big returns. The active guy doesn't want his scrip lent because a falling SP will affect his bonus. But, he likely doesn't have a choice as it is the fund that decides whether to lend or not.

Even if a SF does lend, the custodian does the lending, not the SF, they are not resourced for that. Even once the custodian receives a request from a broker to borrow scrip, it comes from a pool, the custodian usually has multiple clients signed up for scrip lending and it is unlikely the whole pool is lent out at a single point in time. So when the short borrows, the revenue is likely split over multiple lenders.

Even if the SF wanted to know, the broker borrowing the scrip doesn't disclose the identity of the seller anyway. In the case of Macquarie, it could be acting as principal, or it could be acting as Manager, or as agent, hopefully not for one of the real nasty types, the active manager who doubles his bet by having a mix of long and short positions, eg Regal.

Vanguard and State Street MSCI and ASX200 funds are the likely large scale STX scrip lenders IMO, SP movement has no impact on their fees or retention.