RTP estimates returns over time: 96% RTP means a 4% house edge. Volatility...

https://fair-wiki.win/index.php/Does_Session_Timing_Matter_in_Online_Casinos%3F

RTP estimates returns over time: 96% RTP means a 4% house edge. Volatility affects how sharply results swing. In a short session, you can win or lose much more than the average suggests; past results don’t predict what comes next.