Profit = (sell price - buy price)/buy price

If buy price is zero, the division is undefined or the profit is "infinite" because you spent nothing to acquire the asset.

Having a profit of 100% would mean just selling at double the buy price, but nothing stops you at selling at 3x or 4x, having a profit of 200% or 300%.

To give a better example, try with lower and lower "buy price" (approaching zero). You'll see that the profit goes unlimitedly up

I may be wrong, no attacks intended (better to specify lol)