A whie ago I got some capital BPO to make isk by copying, and made a post about it. A little later I got a nyx BPO, back when copies were trading at upward of 3 billion isk each. Later I predicted that nyx BPC prices would continue to fall because of oversupply and market saturation. They have, currently trading at around 1.3 billion -- actually lower than aeon BPC, which have a cheaper BPO. I expect them to continue to fall.
On the other hand, I recently sold my first copy. It might not have earned 3 billion like it would have a year ago, but pulling 1.28 billion out of thin air is still a nice feeling.
Another interesting event recently has been an extremely odd spike in the price of of carrier BPC, trading as high as 170% above their traditional value of around 50 million. It's normalizing at this point, but for a while archon BPC were going for 133 million, almost a third the mineral cost of the ship's hull. Currently they're down to 84 million, but I did get to sell one at 120 while the prices were heading upward.