What the VIX is and how to read it

What it actually measures

The VIX does not measure what has happened, but what the market believes will happen. The Chicago Board Options Exchange (CBOE) computes it from the prices of options on the S&P 500: when investors pay more to protect themselves against a fall, those options get more expensive and the VIX rises.

The figure is expressed as an annualised percentage. A VIX of 16 means the market expects the S&P 500 to move roughly 16% up or down over a year, which works out at a little under 1% a month. It says nothing about direction: it measures the size of the expected move, not its sign.

The levels that matter

There are no official thresholds, but market practice has settled on four bands. Below 12 the market is unusually quiet, sometimes too quiet: these are complacency readings, and they often show up right before a scare. Between 12 and 20 sits the normal range, where the VIX spends most of its time.

Between 20 and 30 there is tension: something is worrying the market and investors are paying up for cover. Above 30 you are in panic territory, and those readings never last long. The all-time highs came in March 2020, with the VIX brushing 83, and in the 2008 financial crisis, when it closed above 80.

One detail that often gets missed: the VIX is asymmetric. It rises far faster than it falls. Equity sell-offs compress weeks of fear into a handful of sessions, while the return to calm is slow. That is why a sharp one-day jump in the VIX tells you more than its absolute level.

Why the “fear index” nickname misleads

The nickname is catchy but imprecise. The VIX does not measure fear: it measures the price of protection. It rises both when investors buy insurance against a drop and when uncertainty is simply high, with nobody sure which way the market will break. A Fed meeting or a tight election pushes it up without any panic involved.

It is also worth remembering that the VIX and the S&P 500 almost always move in opposite directions, but that relationship is not a law. There are sessions when stocks fall and the VIX barely flinches, a sign the market considers the drop orderly and expected.

Contango and backwardation: the term structure

The VIX looks 30 days ahead, but there is a sibling index, the VIX3M, that looks three months out. Comparing the two adds a layer of information the level alone cannot give.

Under normal conditions 30-day volatility trades below three-month volatility: the distant future is more uncertain than the immediate one. This is called contango, and the VIX/VIX3M ratio stays below 1. When that ratio crosses 1 you get backwardation: the market pays more to hedge this week than three months out. It is the signature of a scare in progress, and it usually resolves quickly one way or the other.

What the VIX does not tell you

It does not anticipate falls. It reflects what is already priced in, not a crystal ball: by the time the VIX spikes, the drop has usually already happened. Nor is it any use for timing, because it cannot distinguish a risk landing tomorrow from a diffuse one spread across the month.

And it only speaks about the US market. Europe has the VSTOXX and emerging markets have their own equivalents; a low VIX guarantees no calm outside Wall Street. At Semavor we treat it as what it is: a context indicator that makes sense alongside credit spreads and the yield curve, never on its own.