Interesting math question: When we now start at a negative price tomorrow, what does a percentage change mean? Today, we have got losses >100%, unusual but obviously possible. But if price changes tomorrow from say $-10 to $10, is that again -200%? Does a change from $-10 to -$20 mean +100%?
(I obviously know percentage changes are not made for this)
If I take 10$ to take some asset, and then later sell it for 20$ my return is 30$ and my investment was -10$, so my ROI comes out as -300% which betrays what's going on. So even with ROI, negative numbers throws a wrench in the machinerys typical assumptions.
(I obviously know percentage changes are not made for this)