As long as the cash you're carrying with you was legally obtained and the money is legally yours then there's no limit to the amount of legal cash you can carry around.
Just keep the cash out of plain view and you should be okay from robbery or police.
Sometimes police may seize a large amount of cash if they see the cash in view and suspect you have something illegal but if nothing illegal is happening the cash will be returned to you.
I've carried cash in a locked safe in the amount of $20,000.00 before to go buy a truck out of state and drive it back and I never got stopped with the cash or anything because I kept it out of view in my trunk of my car and I wanted to keep it out of view in case someone tried to rob me of it.
Carry as much legally obtained cash as you want too but just keep it out of view.