I would tottaly disagree, look other coins it's the current price they showing, why would it be different for Petro?
Because they don't have a price.
It's updated since the launch of petro....I didn't really get your answer ,what do you mean by algorithm???
Look at
https://www.cryptocompare.com/coins/utk/post/p_161230/ETH (And read the title of the graph in the Petro case.)
I see points I need to look into it but if it's not price it's too bad.