This cohort cleared out of the deep oversold band it was compressed into a week ago — six of nine names sat at RSI 32-37 on September 18, and only LyondellBasell ($LYB) is still under 40 today — but the two feedstock-exposed petrochemical names, Dow ($DOW) and LyondellBasell, are the exception, and LyondellBasell just lost the trend line it was still holding. Its cushion above its 200-day flipped from +1.0% to -2.5%, the week's one clean structural break, while Dow's own breach deepened again to -10.1%, still the cohort's widest. Every other name narrowed its 200-day gap, and two of them — Ecolab ($ECL) and Air Products ($APD) — now sit above that line, up from one last scan. DuPont ($DD) remains the cohort's one genuinely intact long trend, up 34.64% over the year with the cohort's best alpha at +18.86, even as its short-term trend tag stays downgraded. This scan does not carry the semiconductor-linked names behind yesterday's specialty-process-chemicals move — this cohort is petrochemicals, industrial gases, paints and diversified materials, and the split visible here runs along oil exposure, not chip exposure.

Data as-of the 2026-09-23 close for all nine tickers, including the sector ETF ($XLB). All numbers from the pre-computed chemicals summary. Comparison scan: the September 18, 2026 close.

The RSI compression that defined this cohort a week ago has mostly resolved. On September 18 six of nine names sat between 32.4 and 36.5 — a sector selling as one — and today only LyondellBasell (39.9) remains under 40; the other eight range from 40.6 to 49.9. That relief shows up in the week's returns too: seven of nine names posted a positive 7-day return, led by DuPont at +2.59% and PPG at +2.11%.

The two names that did not join the relief are the cohort's most feedstock-exposed: Dow and LyondellBasell buy crude and natural-gas-liquids inputs directly, and both posted the cohort's worst weeks — Dow -4.75%, LyondellBasell -7.6% — against a broad materials sector (the sector ETF, -0.16%) that was roughly flat. LyondellBasell's week did structural damage: its cushion above its 200-day, which had already been cut from 4.6% to 1.0% last scan, flipped negative to -2.5%, crossing the line for the first time in this series. Dow's breach, already the cohort's widest, deepened again from -9.6% to -10.1%. Dow does have a fresh news pull, dated September 22, but it returned only an earnings-report page and Dow's own investor-relations index — nothing naming a cause for this week's decline. The desk's own oil proxy fell 2.8% on Tuesday, September 22, on reports that Iran could reopen the Strait of Hormuz within seven days, then rose 3.3% today; whether either move touched these two names specifically is not established by any receipt in this corpus.

The other seven names moved the opposite direction on the 200-day check. Ecolab crossed from 1.3% below its 200-day to 1.3% above it — a full reclaim — and Air Products, whose cushion had collapsed to a bare 0.1% last scan, held the line and widened slightly to +0.9%. Sherwin-Williams narrowed its breach from -3.8% to -2.1%, Linde from -4.7% to -2.9%, PPG from -6.5% to -4.1%, and DuPont from -6.0% to -4.7%. The sector ETF itself narrowed from -0.8% to -0.4% but has not yet reclaimed the line. Two of nine names now sit above their 200-day, the same count as last scan, but the membership changed: LyondellBasell dropped out and Ecolab took its place, while Air Products held on.

DuPont continues to be the name worth naming precisely. Its one-year return improved again to 34.64% with alpha at +18.86 — both cohort bests by a wide margin, more than double the next name — while its short-term trend tag remains "strong-down" with a confirmed death cross, the same disconnect this desk flagged last scan. It is a bounce inside a genuinely strong long record and a still-unrepaired intermediate trend, not a contradiction in the data. Note also that this cohort tracks petrochemicals, industrial gases, paints and a diversified materials conglomerate — none of the nine names supply semiconductor-fab process chemicals, the lane that closed up 3.0% with five of five names green in yesterday's session per the market brief, alongside memory and semiconductor-equipment strength. This scan cannot confirm or extend that specific move; the split visible here runs along oil-feedstock exposure (Dow, LyondellBasell down) versus everything else (up), not chip exposure.

• Dow: RSI 40.3→41.5 (roughly flat), trend strong-down unchanged, death cross still confirmed, price $28.73→$28.65, 7D -1.03%→-4.75% (worsened, now the cohort's worst week), 30D -9.51%→-8.87% (roughly flat), vs 200-day -9.6%→-10.1% (deepened again — still the cohort's widest breach), 1Y +19.16%→+25.33% (improved), alpha +4.15→+9.56 (improved). Its September 22 news pull returned only overview and earnings-report pages, no event naming this week's decline.
• LyondellBasell: RSI 43.9→39.9 (dropped, now the cohort's only sub-40 reading), trend weak-down→down, price $61.93→$59.97, 7D -2.76%→-7.6% (worsened sharply, the cohort's second-worst week), 30D -6.25%→-8.02% (worsened), vs 200-day +1.0%→-2.5% (flipped negative — the week's one clean structural break), 1Y +17.54%→+19.06% (improved), alpha +2.52→+3.29 (improved slightly, despite the trend break).
• Sherwin-Williams: RSI 36.5→44.5 (rose), trend down unchanged, price $320.73→$326.46, 7D -0.8%→+1.56% (turned positive), 30D -9.29%→-5.85% (improved), vs 200-day -3.8%→-2.1% (narrowed), 1Y -8.25%→-5.22% (improved from a negative base), alpha -23.26→-20.99 (improved but still the cohort's worst).
• Air Products: RSI 33.5→41.3 (rose, cleared the oversold band), trend weak-down unchanged, price $284.18→$286.97, 7D -2.49%→-0.04% (roughly flat), 30D -6.28%→-6.29% (flat), vs 200-day +0.1%→+0.9% (held the line and widened slightly — did not join the names below), 1Y -2.83%→+3.76% (turned positive), alpha -17.84→-12.02 (improved).
• Linde: RSI 32.4→45.6 (rose sharply, off the cohort's lowest reading last scan), trend down unchanged, price $460.40→$469.72, 7D -1.25%→+1.65% (turned positive), 30D -4.31%→-4.14% (flat), vs 200-day -4.7%→-2.9% (narrowed), 1Y -3.28%→-2.13% (roughly flat, still negative), alpha -18.29→-17.9 (roughly flat).
• Ecolab: RSI 36.4→49.9 (rose sharply), trend down→weak-down (upgraded), price $269.46→$276.72, 7D -2.43%→+0.96% (turned positive), 30D -5.66%→-3.58% (improved), vs 200-day -1.3%→+1.3% (reclaimed the line this scan), 1Y +1.75%→+4.1% (improved), alpha -13.27→-11.67 (improved).
• PPG: RSI 33.5→43.9 (rose), trend down unchanged, price $104.52→$107.20, 7D -0.93%→+2.11% (improved), 30D -8.25%→-5.33% (improved), vs 200-day -6.5%→-4.1% (narrowed), 1Y -4.13%→+0.9% (turned positive), alpha -19.14→-14.87 (improved). Its June 21 news pull is stamped as a failed 429 pull — not evidence of no news.
• DuPont: RSI 40.5→46.0 (rose), trend strong-down unchanged (the short tag stays downgraded even as price and the long record both improved — the same disconnect flagged last scan), price $129.01→$130.88, 7D +1.59%→+2.59% (still the cohort's best week two scans running), 30D -7.64%→-4.24% (improved), vs 200-day -6.0%→-4.7% (narrowed), 1Y +31.64%→+34.64% (improved, still the cohort's best by a wide margin), alpha +16.63→+18.86 (improved, still the cohort's best).
• XLB (ETF): RSI 35.4→40.6 (rose, cleared the oversold band), trend down unchanged, price $49.99→$50.28, 7D -1.88%→-0.16% (roughly flat), 30D -4.82%→-6.16% (worsened), vs 200-day -0.8%→-0.4% (narrowed but still below — the sector instrument has not reclaimed its own trend line).

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, which is why DuPont can carry the sector's best one-year record and alpha while its short-term trend tag reads "strong-down" in the same row. The one-year change, alpha and distance from the 200-day average are the longer-horizon check, and this scan they say something specific: DuPont is the only name with both an intact long record and a strongly positive alpha; Dow and LyondellBasell both show improving one-year returns even as their short-term structure worsens, which means their alpha improvement is coming mostly from the broad index's own weaker one-year window, not from these two names getting stronger in absolute terms. Nothing here is a setup; these are screen conditions.

Capitulation, RSI under 25: None this scan.

Oversold, RSI 25-40: LyondellBasell (39.9) alone — the sole holdover from last scan's six-name cluster, and the one name that also lost its 200-day this week. Low RSI here lines up with genuine structural damage, not a discount.

Neutral to strong, RSI 40+: The other eight. Ecolab (49.9) is the cohort's highest reading and just reclaimed its 200-day. DuPont (46.0) carries the cohort's best long record despite its downgraded short-term tag. Air Products (41.3), Dow (41.5) and XLB (40.6) sit near the bottom of this band; Dow's RSI recovery has not been matched by its 200-day trend, which kept deepening.

Does LyondellBasell's break below its 200-day confirm on the next session, or was this week's -7.6% an overshoot inside a still-positive one-year trend? Does Dow's breach keep widening past -10.1%, and does its fresh September 22 news pull ever return an item naming the cause behind two straight weak weeks? Does Ecolab hold its newly reclaimed 200-day, and does Air Products' thin cushion (+0.9%) survive another week of feedstock-cost pressure on its petrochemical-adjacent neighbors? And does the semiconductor-linked specialty-chemicals lane that moved separately in yesterday's session eventually show up in a watchlist this desk tracks, since none of the nine names here carry that exposure?

• Tape data (price/RSI/SMA/returns/alpha/200-day/1-year/regime): pre-computed summaries as of the 2026-09-23 close — chemicals.
• Comparison figures: 2026-09-18-chemicals (2026-09-18 close).
• Broad-market and materials-sector context (SPY, USO, XLB): market-pulse (same 2026-09-23 close).
• Specialty-process-chemicals and semiconductor-equipment context: 2026-09-22-market-brief (Sector Scorecard: "Specialty process chemicals — +3.0%, five of five").
• Oil/Hormuz corpus: 2026-09-22-cnbc-iran-reportedly-says-it-can-reopen-strait-of-hormuz-within-7-108365945, 2026-09-22-cnbc-oil-prices-fall-for-fifth-day-after-trump-says-u-s-met-with--108365980.
• Cross-sector read: airlines, travel-leisure (same close).
• News/event check per ticker: stocks{DOW,LYB,SHW,APD,LIN,ECL,PPG,DD,XLB}/news/latest.json— Dow's pull is fresh (September 22) but returned only overview/earnings-report pages, no event named; DuPont's pull (September 11) is current with no event named; PPG's and XLB's pulls are marked failed (429 rate-limit) and stale since June 21 and April 29 — not evidence of no news; LyondellBasell, Air Products and Ecolab are stale since June or July 9.research/stock-events/` has no entry for any of the nine in this window. Drivers unestablished at the ticker level from this data.