What the VIX is
The VIX measures how much movement traders expect in the S&P 500 over the next month. Here is how to read it and what it does not tell you.
The VIX is an index that measures how much the US stock market is expected to move over the next 30 days. It is often called the market's "fear gauge" in the news. A higher VIX means traders expect bigger price swings.
Where it comes from
The full name is the Cboe Volatility Index. It is calculated by Cboe Global Markets, which runs one of the largest options exchanges in the US.
The VIX is based on the prices of options on the S&P 500.
A quick word on options
An option is a contract that gives the buyer the right to buy or sell something at a set price before a set date.
Options get more expensive when traders expect bigger moves. That is because a larger move makes the option more likely to pay off.
The VIX works backward from option prices. It asks: how much movement do these prices imply? The answer is the VIX number.
How to read the number
The VIX is shown as a number, such as 15 or 30. It stands for the expected yearly movement of the S&P 500, as a percentage, based on the next 30 days of option prices.
You do not need the math to use it. The general idea is enough:
- A lower VIX means traders expect calmer markets.
- A higher VIX means traders expect bigger swings, in either direction.
There is no official line between "low" and "high". People tend to compare today's reading with its own recent history.
Why it is called the fear gauge
The VIX tends to rise when stocks fall sharply. When markets drop, investors rush to buy options that protect them against further losses. That demand pushes option prices up, and the VIX rises with them.
When markets are rising steadily, the demand for protection eases and the VIX tends to drift lower.
So the VIX often moves in the opposite direction of the S&P 500. This is a common pattern, not a rule.
What the VIX does not tell you
- It does not predict direction. A high VIX means bigger moves are expected. It does not say whether those moves will be up or down.
- It is not a forecast of a crash. It reflects what traders are paying for options today. Those expectations can be wrong.
- It covers a short window. It looks about 30 days ahead, not months or years.
- It covers the S&P 500 only. It is not a measure of every market or every stock.
Spikes and calm periods
The VIX tends to stay in a fairly narrow range for long stretches, then jump during sudden stress. Spikes have happened during financial crises, sharp sell-offs and other surprise events.
After a spike, the VIX has usually come back down over time. But how fast that happens has varied a great deal.
You can read more about the general idea in what volatility means.
Can you invest in the VIX?
You cannot buy the VIX index directly. Some products try to track it using VIX futures, which are contracts that bet on where the VIX will be on a future date.
These products are complex. They often behave very differently from the VIX itself, especially over longer periods. They are mainly used by professional traders for short-term purposes.
Related measures
Cboe publishes other volatility indexes, including ones for the Nasdaq-100 and the Russell 2000. In Canada, there is a similar measure based on options on the S&P/TSX 60, though it gets far less attention.
When news reports mention "the VIX" without other detail, they almost always mean the S&P 500 version.
How people use it
Investors and reporters use the VIX as a quick read on market mood. A rising VIX on a down day signals that worry is growing. A falling VIX during a rally suggests traders feel calmer.
It is one piece of context. It is not a signal to buy or sell anything on its own.
The short version
- The VIX measures expected movement in the S&P 500 over the next 30 days.
- It is calculated from S&P 500 option prices.
- A higher VIX means bigger swings are expected, up or down.
- It tends to rise when stocks fall sharply.
- It does not predict which way the market will go.
This is general information, not investment advice.
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