[k__]

It doesn't sound like anything different from "normal" markets is happening.

You are selling stuff, someone or some people buys a big bunch of it, you think it sells good an rise the price later, now the someone has to buy the stuff for a higher price.

The only difference is the time between the first buy and the second buy for a higher price.

Even if you send your buy-orders at the same time to two different sellers, they don't have to arrive at the same time and if the second seller has "heard" about the first sell, he has enough time to rise the price.