Even if that argument doesn’t convince, he does mention an interesting trade, which is to buy September 30 or 32.50 VIX (Chicago Board Options Exchange volatility index) puts and hedge with at the money SPY (ETF that tracks the S&P 500, whose implied volatility is measured by VIX) puts. What happens is, if the VIX drops as the market rises, the VIX puts make money, but the SPY puts lose value. If the market drops, the SPY puts increase in value, but the VIX puts lose value.

Now the question is, how much of each to buy?

Vega

What we have to look at is, for a move of, say, ten points down in the S&P 500 (which is equal to one point in the SPY) which would make our SPY puts more valuable, how much would VIX drop, which would make the VIX puts less valuable?

How much would the value of the SPY puts increase for a 1 point drop in SPY? Since their delta is near -0.5, they would increase in value by half a dollar.

That is one piece we need.

We need to figure out how much the VIX puts drop in value when SPY drops. To do that we use the SPY vega. Vega of SPY is 0.12 so the change in the implied volatility of SPY would be given by the change in the SPY option value divided by the option’s vega, or 0.5 / 0.12 or 4% for a 1 point drop in SPY. But this is 4% of the implied volatility. Since the implied volatility is 27, this gives a change of the implied volatility of 4% of 27 which is about 1. So the implied volatility would go from 27 to 28.

This change is the underlying that moves the VIX puts. So since the VIX 30 puts have a delta of -0.7, that would change the value of the VIX puts by (-0.7) * (1) = -0.7

So it is these two changes in value that we want to hedge. It looks like we would need about 7 SPY puts for every 5 VIX puts (7 SPY * 0.5 + 5 VIX * (-0.7) = 0).

Where Does The Profit Come From?

One way to figure that out is to look at the vega of the SPY puts and compare it to the delta of the VIX puts. That way, we are looking at the change in the value of the SPY puts when their implied volatility changes (that is what vega measures), and comparing that to the change in the VIX puts when its underlying (the implied volatility of the SPX index) changes.

The vega is the change in the value of the option for a small change in the implied volatility. For the 99 or the 98 SPY put, vega is $0.12 and the delta of the September 30 VIX put is -$0.71. For the September 32.50 VIX put the delta is -$0.89. So we would have to buy six times as many SPY puts as VIX puts. That would make us immune to movements in the implied volatility.

If we bought 7 SPY for every 5 VIX, we would profit from the change in implied volatility calculated above. The VIX puts are six times as sensitive to changes in implied volatility of the SPX as the SPY puts are. If the S&P implied volatility drops, the vega measures the change for the SPY while it is delta that changes the value of the VIX puts.

OK, apparently caused lots of dissenting opinion in regards to slapping on a spread that involved going long VXX and short SPY near term options.

So let me clarify a few points.

This is just a convoluted way around a relatively simple trade, an SPX or SPY calender. So what if we forget VXX and VIX futures exist. The basic thought here is

when volatility caves, I generally would prefer owning calenders. That involves buying longer dated options at likely a higher volatility than I am selling the shorter term options. It gets me short gamma and earns money in the form of time decay.

You have to look at this as two separate transactions though. The short side of the options will earn me money if the realized volatility between now and expiration is less than the volatility I sold them for. Yes, part of that trade likely involves chasing stock into strength and shorting it into weakness. The idea is to lose less doing that than you earn in options attrition.

The long side of the calender is more of a bet on implied volatility at least holding steady. You will not lose all that much time decay, but you are at risk of a move lower in volatility. But if you think options volatility is a buy longer term, you are OK with that.

So combine the two and you are effectively betting on longer term implied volatility to outperform shorter term realized volatility. If you think that’s a good bet, a calendar makes sense.

Using VXX or a VIX future in lieu of a longer dated SPX or SPY option is not identical, but you will win or lose with it in a similar pattern as above.

But it’s important to remember however you chose to go long a longer dated option, it’s not a big deal if you “buy” higher volatility than you sell. It’s two different time frames and two very different bets, there’s no reason they will or should carry the same volatility. A few weeks ago they all did carry about the same volatility. That’s more unusual than not.

So what’s the risk in buying a calendar, or buying VXX and shorting SPY options?

It’s not that some small volatility difference between the two cycles will revert to 0. There are 2 big risks however. One is that realized volatility, which you are effectively shorting, will explode and longer term volatility will not lift as much. You would have got hit massively with that last Fall. Which is why I don’t like this position in a rising volatility environment.

The other risk is that all volatility caves in. Your short volatility will only earn you so much, I mean your options can only go to zero and you will get lousy prices trying to roll them. Meanwhile your VXX or VIX future or longer dated SPY straddle has gotten mauled.

Post getting long here. To be Continued.