VIX Term Structure

The VIX term structure is the curve formed by implied volatility across different horizons, from the front-month VIX futures contract out to longer-dated ones. Under normal conditions the curve slopes upward - contango, with longer-dated volatility priced higher - while during acute market stress it can invert into backwardation, with near-term volatility priced highest, a pattern widely read as a stress signal.

The VIX itself is a single number: a 30-day, index-level implied volatility measure derived from S&P 500 option prices. The term structure extends that idea across time by plotting VIX futures priced for different expiration months, forming a curve rather than one point.

Contango is the normal state: futures for more distant months are priced above the front month, reflecting that more time carries more uncertainty and that longer horizons have more room for unexpected events to occur. This upward slope is also why holding long-dated volatility exposure typically involves a cost, sometimes called negative roll yield, as futures roll down the curve toward expiration.

Backwardation is the inversion: the front month prices above longer-dated months, which tends to happen when a shock is unfolding right now and the market expects the elevated uncertainty to fade once the event resolves. Historically, periods of steep VIX backwardation have coincided with acute market stress rather than calm conditions.

The term structure's shape is a market-wide, macro read, distinct from the SPX-specific, dealer-positioning read that gamma exposure and the volatility regime describe. The two are frequently read together: a market can sit in a stable dealer-positioning regime while the broader VIX curve is flattening ahead of a known event, or the reverse.

It is worth separating the VIX index itself, a continuously calculated snapshot of 30-day implied volatility, from VIX futures, which are separate tradable contracts that settle to the VIX index's value on their expiration date. The term structure specifically refers to the curve of VIX futures prices across their different expiration months, which need not move in lockstep with the spot VIX index on any given day, even though the two are tied together at settlement.

Products and strategies that maintain exposure to VIX futures rather than the spot index are directly affected by the term structure's shape: in contango, continuously rolling from an expiring near-month contract into a more expensive further-dated one creates a structural drag often called negative roll yield, while backwardation can produce the opposite effect. This mechanical relationship between the curve's shape and roll performance is one of the most well-documented structural features of volatility products, independent of any view on where volatility is headed next.

The term structure also interacts with the broader options-selling ecosystem: a steep contango curve has historically made systematically selling near-term volatility and buying it back before expiration a structurally favorable trade on average - a premium that is persistent on average but can turn sharply negative in volatility spikes; this is a description of historical market structure, not a recommendation, which is part of why so much institutional volatility-selling activity concentrates in the front month of the curve rather than further out.