In the week US diesel set record highs and the Fed raised rates for the first time in three years, the airline cohort went up. Every name in the cohort closed green Friday, and Southwest ($LUV) was the standout: +4.43% on the week, the only positive seven-day return in the group, RSI back to 51.3 and price 3.8% above its 20-day, with its 200-day gap narrowing from 9.2% below to 5.5% below. The structural line still moved the wrong way in one place — United ($UAL) crossed from 1.1% above its 200-day to 0.1% below, leaving Delta ($DAL) as the only name in the cohort trading above that line (+6.1%). Delta also stays the cohort's one market-beating trend, up 33.88% over the year with alpha improving to +18.87. Alaska ($ALK) is still the confirmed breakdown — down 29.37% on the year, 11.6% below its 200-day, with the group's worst alpha at -44.39 — though its numbers improved from a lower base. The demand-side damage from this month's fuel shock is visible here in the three-month column, not in this week's: every name sits 16.79% to 33.14% below its 52-week high, and American ($AAL) is down 18.95% over three months.

Data as-of the 2026-09-18 close for all six tickers, including the sector ETF ($JETS). All numbers from the pre-computed airlines summary. Comparison scan: the September 11, 2026 close — a normal one-week gap.

The week's fuel news was one-directional and the tape ignored it. US diesel hit record highs Tuesday as oil stockpiles ran low, Semafor reported September 15, and CNBC wrote September 17 that record diesel prices are already walloping transportation and will spread if energy prices stay high. Jet fuel is a direct cost line for every name in this cohort. Yet all six closed Friday green (Delta +0.24%, United +0.99%, Southwest +1.59%, JETS +0.18%, American +0.15%, Alaska +1.32%) — and the group's monthly losses more than halved from last week's readings. Crude itself came off the boil late in the week: CNBC reported September 17 that oil extended losses as Saudi Arabia offered ship-to-ship crude transfers with its East-West pipeline shut, and Bloomberg reported September 16 that oil held its drop as the kingdom moved to restore the line. Whether the cohort's bounce is that retreat showing up in the airlines is unconfirmed — no news receipt on any of these six tickers covers this week's move.

Southwest is the week's real event and the desk cannot say why. It gained 4.43% over seven days while no other name managed a positive week, its RSI rose to 51.3 — the only reading above 50 in the cohort — and it closed 3.8% above its 20-day average when every other name closed below theirs. Its 200-day gap narrowed from 9.2% below to 5.5% below, its one-year return improved to 26.99% and its alpha to +11.98. Its news was last pulled July 13 and nothing in that pull touches this move; the stock-events record has no Southwest entry in the September 11–18 window. Call the move real and the driver unestablished.

The structural picture is worse than the weekly one. United crossed from 1.1% above its 200-day to 0.1% below it, which leaves Delta alone above the line at 6.1%. Southwest is 5.5% below, JETS 1.0% below, American 6.9% below and Alaska 11.6% below. Alpha improved across all six — Delta +15.99 to +18.87, United -15.8 to -11.85, Southwest +7.49 to +11.98, JETS -9.19 to -6.1, American -15.76 to -11.99, Alaska -51.77 to -44.39 — but the broad index was roughly flat this week, so that is mostly the cohort's own one-year windows repairing, not a step change in relative performance.

The month's fuel shock reads in the three-month column, where the base effects have not scrubbed it out. American is down 18.95% over three months, Alaska 17.7%, Southwest 14.57%, JETS 8.97%, United 8.12% and Delta 5.42%. Every name is 16.79% to 33.14% below its 52-week high. The broad transport proxy is in the same condition — it closed at RSI 31.3, down 7.3% over 30 days and 1.0% below its 200-day on the same close — which is the diesel channel that CNBC described running through trucks and rails, not just jets.

• Delta: RSI 43.3→44.5 (rose), trend weak-down unchanged, price $79.91→$79.62, 7D -0.32%→-0.36% (flat), 30D -11.14%→-4.41% (improved sharply), vs 200-day +7.1%→+6.1% (eased), 1Y +32.21%→+33.88% (improved), alpha +15.99→+18.87 (improved) — still the only name above its 200-day and the cohort's one market-beating trend.
• United: RSI 43.6→43.9 (flat), trend weak-down→down (downgraded), price $109.82→$108.71, 7D -1.4%→-1.01% (roughly flat), 30D -12.23%→-6.11% (improved), vs 200-day +1.1%→-0.1% (flipped negative — the week's structural break), 1Y +0.42%→+3.16% (improved), alpha -15.8→-11.85 (improved).
• Southwest: RSI 38.7→51.3 (rose sharply, cohort's only reading above 50), trend down unchanged, price $39.24→$40.98, 7D -0.96%→+4.43% (the cohort's only positive week), 30D -12.76%→-1.06% (improved sharply), vs 200-day -9.2%→-5.5% (breach narrowed for the first time in this series), 1Y +23.71%→+26.99% (improved), alpha +7.49→+11.98 (improved).
• JETS: RSI 37.8→40.7 (rose), trend down unchanged, price $28.17→$28.22, 7D -2.19%→+0.18% (turned positive), 30D -10.91%→-5.65% (improved), vs 200-day -1.0% (unchanged, still just below), 1Y +7.03%→+8.92% (improved), alpha -9.19→-6.1 (improved).
• American: RSI 36.9→39.4 (rose), trend down unchanged, price $13.01→$12.96, 7D -0.91%→-0.38% (roughly flat), 30D -12.86%→-6.49% (improved), vs 200-day -6.7%→-6.9% (roughly flat), 1Y +0.46%→+3.02% (improved), alpha -15.76→-11.99 (improved) — but the 3-month return (-18.95%) is the worst in the cohort.
• Alaska: RSI 42.1→42.0 (flat), trend strong-down unchanged, death cross still confirmed, price $41.16→$40.54, 7D -2.09%→-1.51% (roughly flat), 30D -13.11%→-1.67% (improved sharply), vs 200-day -10.4%→-11.6% (deepened), 1Y -35.55%→-29.37% (improved from a deep base), alpha -51.77→-44.39 (improved but still by far the cohort's worst) — the only name the desk labels a collapse rather than a pullback.

RSI (Relative Strength Index) gauges how aggressively a stock has been bought or sold over roughly the past two weeks, on a 0-100 scale — under 30 signals an oversold, potentially undervalued stretch; over 70 signals overbought, extended risk; readings in between are neutral. Trend reflects a stock's structural direction based on its moving averages over the past several weeks — it is a short-window read, not a verdict on the multi-year story. vs SMA shows how far price sits above or below its 20-day average. The 30-day column is the one to distrust this scan: every name's monthly loss improved dramatically, and that is mostly the late-August plunge finally rolling out of the trailing window, not fresh strength. The one-year change, alpha and distance from the 200-day average are the honest longer-horizon check — a name above its 200-day with a strong one-year gain and positive alpha is beating the market no matter how a week looks; a name below its 200-day with a negative year and deeply negative alpha is a trend under real test. Nothing in this table is a setup; these are screen conditions.

Capitulation, RSI under 25: None this scan.

Oversold, RSI 25-40: American (39.4) alone sits here, and its RSI is the least interesting thing about it — the name is 6.9% below its 200-day, down 18.95% over three months and 31.03% below its 52-week high. Structure damaged, not merely stretched.

Neutral to strong, RSI 40+: The other five. Southwest (51.3) is the only reading above the midpoint and the only name above its 20-day. Delta (44.5) is the cohort's one intact, market-beating trend. United (43.9) just lost its 200-day and now has no structural cushion at all. JETS (40.7) is the sector ETF sitting a hair under its line. Alaska (42.0) shows why RSI alone says nothing here — a neutral two-week reading on a name that remains broken on every long-horizon measure.

Does United reclaim its 200-day quickly, or does the cross below confirm and leave Delta as the last name standing above that line? Does Southwest's 4.43% week extend into a reclaim of its own 200-day (it needs roughly another 5.5%), or fade back the way every prior bounce in this cohort has? Does the record-diesel cost line CNBC flagged September 17 start showing up in guidance when the group reports, given it has yet to show up in these prices? And does the 30-day column keep improving on its own base effect, or does the three-month damage — still 5.42% to 18.95% across the cohort — start pulling the monthly numbers back down?

• Tape data (price/RSI/SMA/returns/alpha/200-day/3-month/52-week high): pre-computed summaries as of the 2026-09-18 close — airlines.
• Comparison figures: 2026-09-11-airlines (2026-09-11 close).
• Broad-market and transport context (SPY, IYT, USO, XLY): market-pulse (same 2026-09-18 close).
• Cross-sector read: chemicals, travel-leisure (same close).
• Fuel and oil corpus: 2026-09-15-semafor-us-diesel-hits-record-highs-as-oil-supply-fears-mount-pply-fears-mount, 2026-09-17-cnbc-how-record-diesel-prices-will-rip-through-the-u-s-economy-tr-108364417, 2026-09-17-cnbc-oil-extends-losses-as-saudi-arabia-reportedly-offers-ship-to-108364169, 2026-09-16-bloomberg-oil-holds-drop-as-saudi-arabia-moves-to-restore-vital-pipeli-tlfzdrkjh6v400.
• News/event check per ticker: stocks{DAL,UAL,LUV,JETS,AAL,ALK}/news/latest.json— none covers the September 11–18 window (Alaska freshest at August 28; Southwest's last successful pull July 13; United's marked failed and stale since April 29, which is not evidence of no news).research/stock-events/` has no entry for any of the six in this window. Drivers unestablished at the ticker level from this data.