That’s unlikely to be the reason. In fact, during a declining market, people tend to look for other ways to increase their revenue, such as these contests.

It’s more about the nature of the contest and its terms. In this prediction contest, interested members tend to wait until the last moment to submit their entries. This makes perfect sense, as the closer you are to the prediction date, the better your chances of making an accurate prediction.

Just take a look at the contest thread and you'll see that most of the entries were submitted in the last few hours.
Personally, I'll make sure not to miss any of these contests going forward.