I'd like to know whether the number of players or the newness of the game affect such huge bounces.

I think it's moreso the newness of the game (or the large influx of relatively new players) that's causing these bounces. New players will start with scores around zero. A lot of new players coming in a short period of time means a lot of players with scores around zero. As CAPS matures and more and more players' scores naturally move away from zero over time (in both directions), I think we'll see score percentile rankings become less volatile (for those with scores around zero).

There is also the fact that you can't weight your ratings. TMFEldrehad referred to it as the people with the most money getting the most votes, but there's a corollary that affects the individual as well. In the real world, if I thought (for example) that 3M was going to outperform the market some, but that Doral was going to outperform the market a LOT, I might purchase more shares of Doral than 3M.

First, while I don't know where it is on the priority list, I do know that allowing players to 'double down' on a stock has certainly been discussed. While I'd favor allowing for a 'double down', I personally wouldn't push it any further than that. What we don't want is a bunch of players choosing overly concentrated portfolios in hopes of 'getting lucky' and cracking the leaderboard that way - which is what almost inevitably ends up happing in traditional portfolio simulation games.

Regards,

Russell