Cycles News Round-up – September 2026

Here are the cycles-related articles and papers that appeared during September 2026, grouped by forum section. Each item states a specific period. Individual items will also be posted in their own sections.

Scientific Cycles

Cosmology & Astronomy

• Non-linear dynamo waves in magnetized shear flows: a candidate mechanism for the solar cycle (arXiv 2609.30367, Perimeter Institute, Sept 2026). The authors model a shear-driven dynamo wave in the Sun's near-surface shear layer. It gives stable 11-year polarity reversals and also a modulation with an 88-year period, which is in the Gleissberg range. Field strengths and flow speeds are compared with observations.

Geology & Paleontology

• Grand Canyon rocks preserve a 1.2-billion-year record of Earth and the Moon (ScienceAlert, 26 Sept 2026; Lantink et al., Nature Geoscience). Rhythmic layering in the Hakatai Shale records Milankovitch cycles from about 1.25 billion years ago. The authors derive a precession period of about 15,730 years. That implies the Moon was at about 53.8 Earth radii and a day lasted about 19 hours.

Climate & Weather

• IRI ENSO Quick Look, mid-September 2026 (Columbia University IRI, 21 Sept 2026). The weekly Niño 3.4 index reached +3.0 °C. All 22 models forecast a very strong El Niño through the 2026–27 summer/winter. It may rank among the strongest events on record in the 2–7 year ENSO cycle.

Market Cycles

Stock Markets

• US Stocks: Why September Weakness May Be Worth Watching (Matrixport, 4 Sept 2026). Includes a chart of S&P 500 performance through the 4-year presidential cycle. It notes that September has been the weakest month over the last 25 years, and weaker still in midterm years such as 2026.

Commodities

• Sir Gold, the Oil Baron, and Dr. Copper: 15 Stocks for the Supercycle (Thierry Borgeat, The Market/NZZ, 8 Sept 2026). Includes a gold chart showing a 7–8 year cycle, with tops in 1974, 1980, 1987, 1994, 2003, 2011 and 2020, and the next projected around 2028. It also refers to a 39-year cycle of falling interest rates that ended in 2020. (Part 1 appeared on 31 Aug.)
• The commodities supercycle question (Real Assets Adviser, 1 Sept 2026; subscription required). An interview with Aberdeen's Bob Minter. It draws on a data series of the producer price index divided by the S&P 500 going back to 1870.

Interest Rates

• Cycle Mismatch Shapes New Markets: A Deep Dive into the First Full Round of the Sixth Kondratiev Wave (Deep News via Tiger Brokers, 22 Sept 2026). The chief economist of China Fortune Innovation Fund argues that the Fed's rate hike on 17 Sept ended the first asset-pricing cycle of the sixth Kondratiev wave. He also discusses phase mismatch between the Kondratiev, Kuznets, Juglar and Kitchin cycles. This is an interpretive piece rather than a data study.

Bitcoin & Cryptocurrency

• Bitcoin's 4-Year Cycle: What the Record Shows in 2026 (Bitcoin.com, data as of 17 Sept 2026). It tabulates all four halving-linked 4-year cycles and the current drawdown of about 40%. It also scores analysts' "cycle is dead" calls against "cycle holds" calls.

Also noted (late August 2026)

• Infradian rhythms of human heart rate reveal distinct multiday cycle periods in healthy adults (EBioMedicine, 22 Aug 2026). Wearable data show heart-rate cycles from weekly to monthly to seasonal.
• A study in Science (27 Aug 2026) used a 1,000-year coral record and found that recent ENSO temperature swings exceed anything in the preindustrial part of the record.

No qualifying September items were found for Botany, Physics & Geophysics, Sociology, Astrology, Wave Structure of Matter, Exchange Rates, Methods, Mathematics, Music and Harmonics, Scientists and Researchers, or Conferences.