Yes of course there are! I guess i know some of them! Here:
1) Dooglus (5000+ in my opinion
2) Stunna ( 5000+ in my opinion)
3) keepinquiet (1000+ in my opinion)
My estimation:
Dooglus: 7k+
Stunna: 20k+ he owns the biggest dice site, and over 4 billion bets, almost 4 million btc wager. 1% of the house edge, it means he at least has earned over 40k+ BTC.
Addi: 10k+ owns a casino, too
And many biggest casino owners, at least 5K+ btc.