There`s no single manipulator,who is rich and powerfull enough to push the prices down.
There should be a group of big crypto whales and they sell together,forcing the price to go down.When the prices go down,all the small traders start to follow the trend,and eventually the market is manipulated.
Slow and steady decline means small panic.Fast and rapid price crash means big panic.Both scenarios can be created by manipulators.
What do you mean by "artificially bring the prices down to cause panic selling"?
I wouldn't call this decline slow, slow is over weeks but not like today and yesterday. If it wasn't a single manipulator or big whale cashing out, why are the prices going down in this manner? It looks like someone intentionally and deliberately keeps the rate constant to bring it to a point when people think it's over and freak out mindlessly selling their coins. That's what I mean by artificially bringing the prices down to instigate an avalanche-like panic selling. When the prices start crashing on their own.
You think this decline started happening two days ago ?
You need to take a look at the 1 day chart and start counting the candles from when it started showing red, may be you will understand that this started a long time ago.
Just like the OP said, it is always a gradual process, they are whales, they know what they are doing, they come together and then play with emotions of traders to make a pretty good gain from it. Unfortunately, we have a lot of weak hands and traders in crypto, so that makes it even better for them.