Some things to consider
1) What was the investment to generate the 4k in shares? How is it performing? Is there any capital gains or taxes owed?
2) What is the interest rate and term of the loan?
I'm in similar position, have shares which are performing very well, I have outstanding mortgage at competitive market rate and good cashflow to cover the repayments, so for the moment I am happy to let shares continue to grow and continue to repay mortgage at usual rate.
If shares were static or not performing, and you wanted to either cut losses and get out, or just shift things around, and loan was at unattractive rate, then it would seem to make more sense to cancel these out.