@foxwendal
It was for simplicities sake. You're right, I'm both long individual stocks and ETFs as well as short NQ=F and ES=F.
My long term ETF holds are highly correlated to ES=F and discretionary individual company buys are pretty correlated to QQQ. I don't really bother distinguish though as ES=F approximates the US portfolio close enough.
If vix is 60 vs a more long run 20, I probably want to try and sell about 66% of my stocks. I don't want to alter the allocation too much, and it can be quite tedious to go through each individual holding and sell 66% of it. Some of it is already in the minimum lot size such as amazon and google. I only have 100 shares of each and it isn't super practical to sell 66 shares of each of them to get my desired exposure.
I did sell off some though. I use 2800.hk for my HK exposure and sold off a small chunk of that. I also have short MHI, the mini hang seng futures as well as short EWH such that there is always a tradable option to adjust at any hour and not just Hong Kong market hours as would be the case for just 2800.hk.
When expiry comes as it did for the March 20 ES=F, I just roll it gradually into the next lead maturity.
In short I would say it's for:
Ease of calculation: Just short (1-(20/vix)) percent of my SPX Delta.
I can adjust the above 24 hours a day (not that I try to. I'm pretty settled at my current level).