Only 2.9BTC around volume and market is already getting corrected. Don't know how you concluding sling going to polo. 
May be this high volume is due to similar event like this one https://bitcointalk.org/index.php?topic=1243932.msg16761673#msg16761673
Found in their ANN someone's account got hacked on 21 october which causes sudden trading volume pump of 6 btc, worth to check.