Because of the same reason why rates droppend when the price rised
But also because more coins are wagered when the price is low, thus they have a bigger budget to spend.
I would like to know from online casino owners that does the rise and fall of bitcoin really effect that much in wagered coins, I know it will effect but only if the rise or fall is of over 300$ .. because its normal with bitcoin to bounce in between 200$window..! but I would like to hear from owners how much does it really effect because if the wagered amount really go up then the rates should be modified.
I'm sure it does...if one BTC is $300...some people may be willing to gamble 1BTC, if the value is $1000, then less people will be willing to risk 1BTC