Browser based Gann analysis software, named after an observatory in the Queensland hinterland and built on a century of cycle research.
Crohamhurst is a calculation engine for traders who use W.D. Gann and planetary cycle methods. It computes Square of Nine price levels, the Bradley siderograph, planetary ephemeris positions and aspects, dominant market cycles and historical planetary analogs, all in your browser from price data you supply. It is built and run in Australia by Dutch Digital Dynamics Pty Ltd. The rest of this page is the story behind the name, and why we take cycle computation seriously.
Crohamhurst Observatory stands in the Sunshine Coast hinterland of Queensland, Australia. It was established in the early twentieth century to study the relationship between astronomical phenomena and long-range weather patterns.
The observatory's most celebrated resident was Inigo Jones, successor to Clement Lindley Wragge, who spent decades at Crohamhurst developing a forecasting method that drew explicitly on planetary cycles. Jones believed that the movements of Jupiter and Saturn created recurring drought and flood rhythms across Australia's agricultural regions, and he published long-range Queensland pastoral forecasts on that basis for decades.
Whether you accept his methodology or not, Jones's work stands as one of the most serious attempts to systematise cycle-based forecasting using real data over a long time horizon. His forecasting records from Crohamhurst span decades and remain archived in Queensland.
William Delbert Gann (1878–1955) was an American market analyst and trader who developed a suite of technical and astronomical tools for timing markets. His published works, including The Tunnel Through the Air, How to Make Profits in Commodities and his trading courses, describe a framework linking price geometry to time cycles derived from planetary motion.
"There is a definite relation between time and price. When time and price balance, a change in trend is indicated."
W.D. Gann
Gann's specific tools are the computational core of Crohamhurst: the Square of Nine, the Wheel of 24, geometric angles on price charts, and the Bradley Siderograph developed by his contemporary Donald Bradley.
The name Crohamhurst is deliberately chosen. Both Jones and Gann were serious empiricists who collected long data series, built systematic frameworks, and tested their methods against real outcomes rather than simply theorising. Crohamhurst the platform inherits that empirical spirit. The tools are built on modern numerical computation rather than hand-drawn charts, but the methodology is unchanged from what Gann documented.
Queensland meteorologist who operated from Crohamhurst Observatory and developed long-range weather forecasting methods based on the 11.86-year Jupiter cycle and 29.5-year Saturn cycle. His forecasting records for Queensland's pastoral regions span over three decades.
American commodities and stock trader who developed the geometric and astronomical market analysis tools that bear his name. Author of multiple trading courses and books. The Square of Nine, Wheel of 24, and time-price geometry methods originated with Gann.
Bradley developed the siderograph, a planetary aspect-weighting model that generates a composite market timing indicator. The siderograph does not predict price direction, only potential turning points. It has been used continuously since its publication.
Crohamhurst provides five distinct analytical tools, each rooted in a specific aspect of the Gann tradition:
The foundation of all astro-technical work. Accurate geocentric and heliocentric planetary positions computed using the Skyfield library and NASA's DE421 ephemeris, the same dataset used by observatories and space agencies worldwide. Accurate to sub-arcsecond precision from 1900 through 2050.
Donald Bradley's system assigns numerical weights to planetary aspects (conjunctions, oppositions, trines, squares, and sextiles). The weighted sum accumulates over time to produce a line that Bradley associated with market turning points. Crohamhurst computes it for any date range you specify.
Gann's geometric spiral maps numbers onto a grid from a central value outward, creating a structure where prices on the same angular axis are geometrically related. Anchor a price, choose an axis (cardinal or diagonal), and the Square of Nine returns the harmonic levels above and below: potential support and resistance candidates.
Modern FFT (Fast Fourier Transform) analysis applied to price series. The scanner detects the dominant repeating cycles in your data and returns their periods, phases, and relative power. The Hurst exponent accompanies each analysis to characterise whether the series is trending, random, or mean-reverting.
Gann believed that history repeats in cycles tied to planetary positions. The Analogs module scans up to 100 years of astronomical history to find the dates when the planetary configuration most closely resembled today's sky. What did markets do at those similar configurations in the past?
Crohamhurst does not assert that astro-technical analysis is scientifically proven to predict markets. We provide the computation. Whether correlations you find are meaningful is for you to judge. This is a research and exploration tool, not a trading signal service.
Crohamhurst is designed for traders and researchers who already understand the Gann tradition and want computational tools, not tutorials or hand-holding. Every module includes documentation explaining the methodology, but the platform assumes you know what you're looking for.
Dutch Digital Dynamics Pty Ltd (ABN 86 081 237 087) is an Australian company. The platform is hosted on Australian servers. Your data is processed locally and not transmitted to third-party analytics services. We comply with the Australian Privacy Act 1988.