Puts are expensive because the cost of borrowing? You are mixing two different instruments. Borrowing occurs when you short NOT when you buy puts. Puts are exp

Puts are expensive because the cost of borrowing? You are mixing two different instruments. Borrowing occurs when you short NOT when you buy puts. Puts are expensive because of the stock's volatility (and exercise price). The higher the volatility, the more expensive the option (call/put) is. Just check the math of the Black-Scholes options pricing model.