Multiply by 2 - Python

The input takes numbers until a negative number is entered, every number before that is multiplied by 2 and the result is printed and formatted to the 2nd digit after the comma. I've tried the following, however the loop just continues endlessly giving me only 1 result, how can I make it stop and multiply with the next input instead?

x = float(input())
while x > 0:
    result = x * 2
    if x < 0:
        print('Negative number!')
    print(f'Result: {result:.2f}')