Ten years ago today, we witnessed that largest one-day VIX spikein the nearly three decade history of the VIX. On that day, the VIX rallied from a prior close of 11.15 to 18.31 – a 64.2% gain. The move came in conjunction with a 3.5% decline in the SPX (large, but nothing like what would follow during the next two years) and followed overnight concerns related to the Chinese government raising interest rates to discourage speculation. The fears in China were