Maybe it's because of the suddenly increase of the bitcoin price these past days and bitcoin future is also kicking but i doubt that there will be a bull run on this one. it's because bitcoin is also increasing in price.
I think the recent increase in the Bitcoin price is only a small part for this record volume. I believe that most of this volume is from new investors wanting to try to trade something that has to do with Bitcoin. You know, like investors that are still shy from going directly into Bitcoin, so they just want to dabble in it a little bit, so they trade futures. There is a lot of hype building up with ETFs and things like that. This is definitely sparking interest in other investors that haven't traded Bitcoin yet.
I think this is a future indicator that Bitcoin is about to see another exponential price increase. Not only is the CME Futures volume picking up, but these last few weeks the daily Bitcoin transaction volume has been increasing as well. More people are gaining interest in Bitcoin as a potential future, long-term investment/store of value. This increased volume is very bullish.