Predicting the price of a product that lacks intrinsic value is difficult. Typically the price reflects demand; if supply is thin and demand high, the price goes up. Once demand dries up, the price falls; typically precipitously.

So, the question might be, how do you predict future demand for Tulips?

This page has an interesting backgrounder on the phenomenon.

There are many scientific methods for predicting price based on the current price, including stochastics via Markov chains, Bollinger bands, Kaufman Adaptive Moving Averages, etc, etc.