The market is made up of people. And people are influenced by a number of factors. Usually, greed and fear.
So, to honestly answer your question: No one can tell you exactly why the shares are priced the way they are.

Past examples:

Lately, the price has been going down. This is mostly due to so many new companies offering shares for the first time (IPOs). People want to "get in on the ground floor and ride it up." In order to get funds to do this, they sell shares they have in existing companies (like bASIC-MINING). As more people sell, the price goes lower and lower. Is it gambling? Sure, but it's also investing... high risk investing, but investing. (Greed)

The price of bASIC-MINING has also sharply risen when creativex announced new equipment added to the asset. This makes sense as more equipment means more dividends. (Greed)

The price tanked when there was a hint of chance that the US government would introduce regulation. (Fear) This blew over and the market gradually recovered. (Mostly)