Just had my MS70 silver gilt 1 BTC sell for 3.5 WBTC on 4k, not sure how to feel tbh. Listed at fairly high prices because I wasn't that motivated to sell but apparently someone really wanted one 
txid: https://etherscan.io/tx/0x5d2dea2ab81fc8db685a4646b9b8cc5bd777a97714a01e3ba9542285e86f1c4c
txid: https://etherscan.io/tx/0x5d2dea2ab81fc8db685a4646b9b8cc5bd777a97714a01e3ba9542285e86f1c4c
I'm quite surprised about the lack of discussion around this sale. This is great news for owners and the highest premium I've seen one of these coins fetch in years (in BTC terms at least)
I'll be keeping a close eye on 4K going forward