I suspect tons of insider trading going on. For example look at the charts before major news. I.e. the dumpings before polo delistings and accumulation before listings.
well part of it is always a public knowledge. for example exchanges delist coins that are dead or are not generating them enough profit. and you can see this on the charts and by simply looking at the history of trading volume. but that doesn't warrant a pump though.
the same goes for listing. coins that are good, for example a new coin that has been performing well enough and has a high daily volume will definitely be added to more exchanges sooner or later and accumulation is usually easy to spot on the charts.