I hold my money in my hand. I can not even remember the last time I used wallet, it always gets lost especially when I make use of public transport. Most of what I purchase these days I make electronic transfer to the seller.
But if I can I hold my money in my hand tight.
In my experience, it has never been safe to put your money in the back pocket. You can lose the money at any time without even knowing it. Taking a purse with you will be the best way to keep your money safe with you.