I saw Russian thread about waves and I saw there are the same questions. There are 2 options - first of all usually waves team or someone involved to waves team buy some tokens. They usually supports their token. of course this is not official, but people who looks like insiders wrote about that. The second one - there are one huge seller. Nobody knows who is this, but looks like this is someone from older investors or something and of course all market was red, so this is multiple effect.