RE:RE:HVUFriday is part of it as options and futures expire. But it doesn’t explain a 10% drop.
Also the SP VIX index is at 17. The FTSE VIX is at 26 (30 on Friday) and he NiKK Vix is at 32 both due to BREXIT. You can’t have major markets with that type of volatility imbalance for long. The NIKK VIX is always an oddball as the Japanese are very risk adverse. But the FTSE VIX should be closer to the SP VIX
If BREXIT is yes, we could see the SP VIX at 25 in no time. If it’s no, back to 15 and the FTSE VIX will drop below 20 and more in line with the SP VIX