Can a day with bad CTR affluence EPC

After posting a message in a news forum

[jetteroheller]

Seems I should stop wasting my time in the forum of some news web sites.

I wrote Monday a post in a news forum related to the theme of the message.

The ad channel of this domain had 75% more impressions but even some clicks less than on Sunday.

So CTR went about 40% down.
EPC went also 40% down.

Next day usual impression and clicks, but EPC still down.

[alika]

I guess this is one of the mysteries of the world. I have days with great spikes in CTR, only to see EPC climb down the next day. I've had days with bad CTR but EPC increases the following day. Adsense is one rollercoaster ride that I'd rather spend my time building content than analyzing every grunts and hiccups.