IB borrow rate for BIMI 860%

[Sig]

As I understand it, with underlying at the strike, Put + Carry = Call + Div

So if there's a pending dividend, it increases the put's premium, relative to the same series call. And if the interest rate rises, it increases the call's premium relative to the same series put.

But with a synthetic short, it bumps the put's premium up. Is this because the borrow rate is paid out as well? If so, I don't see how it fits into the formula. Can you provide an example? TIA.

Put call parity doesn't hold with a stock that's got a high borrow rate...just work through the no arbitrage scenario of shorting the stock opposite your synthetic position and the reasoning will be obvious.