but I still can't help but feel it is kind of unfair.
let's say I predict $50,000 price today that price is $5,000. but as we get to November 2020 price reaches $100,000 so even if I have the biggest weight I am never going to win since those who make the best in the final month will definitely win it since they are closest to the event and can make the best prediction.
this can work with sports bet,... but it won't work for price bets.
Any suggestions on how to improve it?
as I said this design works well with other types of bets like sports bet because not that much changes that can drastically affect the result of a match. but when it comes to price speculation the timing matters so in this particular case a deadline for making bets would be best. for example for 2020 thing you can limit participation to end of 2018 so there is a whole year time between the end of the participation deadline and the end of the actual price deadline.
also it would be great if smaller time frames were also added alongside this 2 year deal. with a bet that is for the price in a month from now this current design makes more sense.