Insertion sort algorithm doesn't bother about last number in list

I’d like to write a insertion sort algorithm. I’ve almost finished it, but the function itself seems to not even bothering about last number. What could be wrong here?

def insertion_sort(user_list):
    sorted_list = []
    sorted_list.append(user_list[0])
    for index in range(0, len(user_list)):
        if user_list[index] < user_list[-1]:
            for reversed_index in range(index, 0, -1):
                if user_list[reversed_index] < user_list[reversed_index-1]:
                    user_list[reversed_index], user_list[reversed_index-1] = user_list[reversed_index-1], user_list[reversed_index]
                    print(user_list)

    print("\n\n", user_list)


if __name__ == '__main__':
    user_list = [4, 3, 2, 10, 12, 1, 5, 6]
    insertion_sort(user_list)

>Solution :

replace if user_list[index] < user_list[-1] with if user_list[index] < user_list[index-1].

While doing insertion sort, we compare two consecutive elements to check if they are out of order. Comparing with the last element of user_list seems like a typo.