01 — Anatomy & Naming

A spread is a verb spelled in two months.

Each contract is CL + month-code + year. The exchange quotes the difference of two legs as one tradeable instrument. We read them in plain English — front month first: Dec–Dec, Dec–Jun, Jun–Jul.

MONTH CODES · F G H J K M N Q U V X Z = Jan…Dec
CLZ5–CLZ6
Dec25 – Dec26

Try Z / Z → the classic 12-month Dec–Dec "red". Or Z / M → Dec–Jun. Or M / N → Jun–Jul, the most-liquid 1-month.

The two readings of one number

The spread = front − back. Its sign is the entire market regime in one tick:

SPREAD > 0 · BACKWARDATION
Front richer than back. Tight supply, scarcity premium, inventories draining. The curve slopes down in time. Bullish for holders — you earn positive roll yield.
SPREAD < 0 · CONTANGO
Back richer than front. Glut, storage filling, weak demand. The curve slopes up. Holding costs you roll yield — it bleeds passive ETFs like USO ~10–15%/yr and is exactly what a calendar trader harvests.
WHY SPREADS

Low-vol by construction

Both legs share the oil price (LEVEL). Long one, short the other and that shared move nets out — you're left holding only the shape. Lower vol → lower drawdown, the hard constraint.

WHY SPREADS

They mean-revert

An outright price trends and gaps. A spread breathes around a fair value tied to storage economics. That's a statistical edge an outright simply doesn't offer.

WHY SPREADS

Capital-efficient

SPAN's inter-month margin credits make a calendar spread cost ~10× less margin than an outright — the structural reason this is viable on a small prop account.

"Price tells you where oil is. The curve tells you what the market is afraid of."