Is mortgage rate related to sotck market? If so, how? I heard we are due for a market crash in Oct.
The stock market and the bond market compete for the same dollars. The usually move in opposite directions but not always. When the stock market is doing poorly investors move their money to the bond market as a safe haven. The more people invest in the bond market the price of bonds will increase and rates...

Private Mortgage Insurance (PMI) is designed to protect the lender in the even a borrower fails to pay the mortgage. It is not in anyway designed to benefit the borrower. So, the answer to your question is no.