Executive Summary The 3:2:1 crack spread serves as a primary proxy for gross refining margins, calculated as: 3:2:1 Crack Spread=2×PGasoline (bbl)+1×PDistillate/Heating Oil (bbl)−3×PCrude (bbl)3\text{3:2:1 Crack Spread} = \frac{2 \times P_{\text{Gasoline (bbl)}} + 1 \times P_{\text{Distillate/Heating Oil (bbl)}} - 3 \times P_{\text{Crude (bbl)}}}{3} where prices are typically futures-settled (e.g., WTI/RBOB/NYH HO for USGC benchmarks; Brent equivalents or regional baskets for Europe).…