Summary
RBOB NYH barges averaged 329.27 c/gal, down 7.60% on September, and lost 10.92% between 1 and 30 October as US gasoline stocks rose 4.4 million barrels in the three weeks to 23 October (EIA). The octane premium unwound: alkylate ended 41.18 c/gal over Gulf CBOB from 78.88. New York reopened its premium over the Gulf and Line 1 line space was positive on all 22 sessions. Chicago CBOB rose 65.93 c/gal in two sessions when the Joliet reformer went down on 20 October. The Pasadena curve moved to front collapse.
Price trends
RBOB NYH averaged 7.60% below September and fell in every week of the month.
- RBOB NYH barges averaged 329.27 c/gal against 356.36 (-7.60% MoM; up 70.51% YoY against 193.11); high 358.26 on 1 Oct, low 315.41 on 27 Oct.
- US gasoline stocks built and four-week demand ran 0.7% below a year earlier (EIA).
- Colonial Pasadena CBOB A averaged 308.58 c/gal (-6.51%) and set its low of 288.75 on 27 Oct as Gulf Coast gasoline stocks rose 4.8 million barrels in the three weeks to 23 Oct (EIA); every grade fell except Chicago CBOB, up 0.62%.
| Week | Avg RBOB NYH (c/gal) | WoW Change |
|---|---|---|
| W1 (1-2 Oct) | 354.25 | |
| W2 (5-9 Oct) | 336.85 | -4.9% |
| W3 (12-16 Oct) | 328.99 | -2.3% |
| W4 (19-23 Oct) | 321.44 | -2.3% |
| W5 (26-30 Oct) | 319.80 | -0.5% |
Source: GX Go
Cross-commodity dynamics
The octane premium unwound: alkylate ended 41.18 c/gal over Gulf CBOB from 78.88.
- Alkylate over Colonial Pasadena CBOB A averaged 59.65 c/gal (September 85.13); reformate's premium went from 166.88 to 63.17.
- Premium over regular averaged 36.39 c/gal at NYH barges (September 44.81).
- With winter grade on both coasts, cheaper high-octane light blendstock displaced alkylate and reformate.
- The D6 RIN averaged 188.05 c/gal (-8.84%) and fell to 163.50 on 21 Oct after EPA proposed on 13 Oct to push 770 million reallocated 2025 RINs into 2026 and 2027.
Market activity
Gulf CBOB volume fell 8.8% and moved into the 13.5 psi A4 grade.
- On the aggregate of the month's trades (not published index volumes), CBOB A grades traded 56.2 million bbl against 61.6 million (-8.8%); A4 took 34.8 million bbl from 8.7 million.
Cross-regional dynamics
New York reopened its premium over the Gulf, and Chicago rose 65.93 c/gal in two sessions.
- CBOB NYH barges averaged 21.00 c/gal over Colonial Pasadena CBOB A and Line 1 line space averaged 5.27 c/gal (September -0.50): East Coast runs of 77.9% to 81.7%, against 92.0% to 93.7% a year earlier, left New York drawing on Gulf barrels (EIA). The Bayway refinery kept running under a lockout from 19 Oct.
- Chicago CBOB rose from 334.22 c/gal on 20 Oct to 400.15 on 22 Oct, 106.09 over Pasadena CBOB A, after the Joliet refinery's 50,000 b/d reformer went down on 20 Oct; Group 3 Suboctane V averaged 25.90 over Pasadena (September 11.31) and closed 2.12 over.
- CARBOB Los Angeles averaged 67.60 c/gal over Pasadena CBOB A (September 85.79), with winter blend allowed in California from 28 Sep and West Coast runs at 95.1%, against 74.7% a year earlier (EIA).
Curve structure
Front collapse at Pasadena: M1 fell 33.33 c/gal while M12 fell 3.43.
- M1-M6 crossed below zero: November delivery closed 6.62 c/gal under April 2027, inside the spring switch to summer grade.
| Spread (RBOB Colonial Pasadena, c/gal) | Month-Start | Month-End | Change |
|---|---|---|---|
| M1-M2 | +22.78 | +5.67 | -17.11 |
| M1-M6 | +27.65 | -6.62 | -34.27 |
| M1-M12 | +78.21 | +48.31 | -29.90 |
Source: GX Go
Price volatility
Base gasoline stayed calm; octane blendstocks swung the most in six months.
- CV measures how far prices typically sat from the monthly average: RBOB NYH's 3.39% means about 11 c/gal either side, against 14 in September.
- Alkylate (10.59%) and reformate (12.30%) hit six-month highs: alkylate sat about 39 c/gal either side, against 26 in September and more than three times RBOB's.
| CV (%) | May-26 | Jun-26 | Jul-26 | Aug-26 | Sep-26 | Oct-26 |
|---|---|---|---|---|---|---|
| RBOB NYH barges | 5.72 | 2.83 | 4.47 | 5.86 | 3.82 | 3.39 |
| CBOB A Colonial Pasadena | 6.94 | 3.38 | 4.50 | 3.75 | 3.69 | 4.50 |
| CARBOB Los Angeles | 7.31 | 2.49 | 5.51 | 7.90 | 7.16 | 4.94 |
| Alkylate USGC | 5.60 | 2.51 | 4.91 | 7.51 | 6.38 | 10.59 |
| Reformate USGC | 5.97 | 2.48 | 3.83 | 5.31 | 10.39 | 12.30 |
Source: GX Go
Something to watch
Octane into winter blending:
- Observation: alkylate closed 41.18 c/gal over Gulf CBOB A and premium over regular 19.00 at NYH barges.
- Why it matters: the premium kept falling with a Midwest reformer down, so the pool is long octane until a Gulf unit goes down.
- What to monitor: alkylate and reformate against Pasadena CBOB A; premium over regular.
New York against the Gulf:
- Observation: Line 1 line space closed at 7.12 c/gal and CBOB NYH barges 18.12 over Pasadena CBOB A.
- Why it matters: East Coast runs near 81%, against 93% a year earlier, keep New York reliant on Colonial barrels.
- What to monitor: Line 1 line space; East Coast refinery utilization and gasoline stocks (EIA); the Bayway contract vote.
Chicago after the spike:
- Observation: Chicago CBOB closed at 290.65 c/gal, 10.38 under Pasadena CBOB A, after 106.09 over on 22 Oct, with the reformer back by 27 Oct.
- Why it matters: one reformer moved Chicago 106 c/gal over the Gulf in two sessions; the interior premium reacts to any unit outage.
- What to monitor: EIA Midwest refinery utilization and gasoline stocks; Chicago CBOB and Group 3 against Pasadena CBOB A.
Note: All figures, prices and market activity referenced in this report are based on the period 1 to 30 October 2026.
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