Yes they are manipulating, you are exactly right

Well I'm using Kucoin and I buy and sell these Odyssey coins. there are some gamblers or something like that manipulating coin prices by buying coins when they want them increase and sell to decrease coins worth. it sound normal but it is annoying when they bought 10 coins (equals to 80 cents) more than 20 times or more in just seconds. People using android phones to buy and sell these coins see only if it is rising (green) or dropping (red). same thing happens in trinity network credits (TNC) when you check the markets on coinmarketcap.com, you can see these two coins are on couple markets like kucoin, gate.io. anyways it looks like some gamblers which are like to be driven away from casinos found a new area at least in Kucoin.com. just register to kucoin and see what happens. just watch for 15 minutes (they will appear) then decide what you want to do.