There is no algorithm
They are cutting bank rates manually
Instabuy is draining ekschanges from big buyers and none is interested in rebuy sold minexcoins, wich is really strange as they sold mist of them at much higher prices...
People who bough mnx at $10+ are regretting that move and even with such low price i wouldnt risk to buy more
And we have that strange move with few levels of ban rates, problems with the cards etc.....
Honestly after year of such a price dumping i will be really surprised if the price goes to at least $5