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Roll yield

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Roll yield

Roll yield is the profit or loss from closing an expiring futures contract and opening a new one at a different price. It's the hidden cost (or gain) that diverges commodity ETF returns from spot price moves. Understanding roll yield is essential for any commodity investor.

The mechanics are straightforward. Suppose you hold June crude oil futures at $85 per barrel. June expiration approaches; you sell the June contract at $85 and simultaneously buy the July contract at $84. You've locked in a $1/barrel loss on the roll. Over 1,000 barrels, that's $1,000. If this happens every month, you're losing 1.2 percent annually just rolling—before considering storage costs or index rebalancing drag.

Negative roll yield occurs in contango (near prices lower than far prices). You sell cheaper, buy dearer, lose money. In crude oil contango of $3 per barrel spread (one month apart), you lose $3 per barrel every single month you roll—a compounding drag. Over a year, you could lose 30–40 percent of returns to negative roll yield alone. This is why passive long-only commodity exposure has historically underperformed spot commodity prices.

Positive roll yield occurs in backwardation (near prices higher than far prices). You sell expensive, buy cheap, make money. The 2008 oil crisis, when nearby crude was trading above distant contracts, was a bonanza for roll yield. Investors who held crude futures made money rolling forward at profit, on top of spot price appreciation. This is why timing commodity purchases to coincide with backwardation is a key principle.

Oil roll yield has been historically negative, averaging -2 to -4 percent per year. This is because oil is typically in contango (storage is cheap, supply is abundant). Gold roll yield is much smaller in magnitude because gold storage is far more expensive relative to the commodity price—the forward curve is flatter. Natural gas is more variable: summer contango (storage building) is steep; winter backwardation (storage draining) is severe.

The UNG (iPath Series B Bloomberg Natural Gas ETN) is the classic warning case. UNG holds front-month natural gas futures, rolling continuously. During 2020–2021, natural gas was in steep contango (Permian producers were burning off excess gas cheaply). UNG lost money rolling despite soaring spot gas prices. A trader who bought UNG at the 2020 lows and held through 2021 would have lost money despite spot natural gas prices tripling. The ETN tracked its index; the index suffered from negative roll yield.

Historical rolls matter for total return calculations. Consider an investor who bought crude oil futures in 2007 (when oil was $70/barrel). Oil rallied to $147 in 2008, then crashed to $30 in 2009. If the investor held through the rolls, they captured spot appreciation but lost money rolling in contango. Their total return was lower than spot prices alone suggest. Conversely, an investor who bought in late 2008 (right after the crash, in backwardation) made money rolling, amplifying returns.

Professional commodity traders actively manage roll mechanics. Rather than rolling at the last moment (when bid-ask spreads are wide and slippage is high), they roll gradually across multiple days. Rather than rolling the same contract month, they construct calendar spreads—buying one month, selling another—to isolate and profit from curve moves independently of spot prices. This is beyond the scope of passive investors but illustrates why commodity trading is genuinely complex.

For ETF investors, the lesson is simple: check the fund's forward curve environment. In steep contango, expect negative drag. In backwardation or flat curves, expect better tracking. Some commodity ETFs use alternative indices that weight contracts differently or rebalance less frequently to minimize roll drag. Understanding these details separates informed investors from return-blind ones.

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