Nah, there should be an option for such predictions as long as the the results can't seems to be known by everyone including the player itself until after the market is been opened and inter club negotiations begin.
Although, this option should only be available on the future prediction market not sport betting bookies, as it gives you more time for results.
Because in the end people will make false rumors as bait so that many will bet that the player will be transferred and such, this will be a trap for many people because there is also no clear confirmation by the club and the player, completely the transfer of the player is a club secret, before finally being leaked itself and giving a sign that the player will be transferred.
The option that may be able to be used of course this will really be a blind bet before there is any direct information from the club, or rumors from the people closest to you.