Blue line: HELI Index (normalized, 0–1 scale); Black dashed line: Solar Cycle (Wolf number, 11-year harmonic); Red vertical dashed lines: Economic Peaks (1749, 1801, 1859, 1917, 1968, 2024); Green vertical dashed lines: Economic Bottoms (1775, 1833, 1889, 1944, 1996, 2045); X-axis: Years 1750-1900 and Years 1900-2050, in strict chronological order.
HelioEconomic Leading Index (HELI) for USA, Russia, China, and Great Britain (1900-2024). Blue line: USA; Red line: Rusia; Green line: China; Brown line: Great Britain; Red vertical dashed line: Economic Peak; Green vertical dashed line: Economic Bottom.
Rather than viewing economic expansions and contractions as purely the result of credit, technology, policy, or random shocks, Valkov argues that solar magnetic activity provides the underlying rhythm. He posits that every fifth solar maximum plants the seed for a major economic peak approximately five to ten years later, while solar minima trigger the deepest troughs.
This pattern establishes a dominant approximately 55-year supercycle (roughly five Schwabe cycles) that has governed global economic turning points from pre-industrial 1750 through the industrial and modern eras, spanning diverse economies including the USA, UK, Russia, China on a panel of 12 major countries.
» These findings have important implications for economic theory, forecasting, and policy. « Next solar minimum (Cycle 25/26 transition) anticipated around 2030–2031.
Valkov posits that solar activity influences economies through four interconnected channels:
The first channel involves biophysical and health effects: geomagnetic storms and solar radiation variations are argued to affect human health, melatonin levels, mood, and cognitive function, citing medical literature on increased depression, suicides, and risk aversion during periods of high solar activity.
Second, technological disruptions are a growing concern in the modern era, as space weather impacts infrastructure, satellites, and power grids.
Third, Valkov includes agricultural and climate channels through subtle influences on weather patterns and crop yields, though he acknowledges this is a weaker driver for the regular 11-year solar cycle.
Finally, the psychological and behavioral channel is considered crucial, suggesting that collective mood shifts drive investor sentiment, risk-taking, and economic decisions, a concept that builds on research by Krivelyova and Cesare Robotti (2003) and similar studies.
The key innovation of Valkov's work, however, is the proposed 55-year rhythm: every fifth solar maximum (a period of 54–60 years) marks a "super-peak" corresponding to major economic booms and the subsequent crises that occur when the underlying expansion ultimately overshoots.
Valkov's theory builds on earlier ideas from Jevons (1875), Chizhevsky (1924), Garcia-Mata (1934), and the Foundation for the Study of Cycles, but he elevates them with rigorous modern statistical methods and an extraordinary historical dataset covering twelve major economies, including the United States, United Kingdom, Russia, and China—both before and after industrialization.
» The HELI index outperforms traditional leading indicators in predicting major economic turning points, offering
policymakers and analysts a new interdisciplinary tool for risk assessment and macroeconomic planning. «
At the heart of Valkov's paper is the HelioEconomic Leading Index (HELI), a composite indicator that combines smoothed Wolf sunspot numbers (inverted and appropriately lagged) with macroeconomic variables such as unemployment rates, GDP growth, and industrial production. Spectral analysis, Granger causality tests, and principal component methods show that the HELI index explains approximately 78% of the variance in global business-cycle turning points over nearly three centuries—a level of explanatory power rarely achieved by conventional leading indicators.
The alignment is striking: Major economic peaks repeatedly occur near every fifth solar maximum (for example, the Roaring Twenties, the mid-1960s–early-1970s boom, and the 2014–2020 expansion), while the deepest depressions and recessions cluster around prolonged solar minima (the 1930s Great Depression, the early 1980s double-dip, and the 2008–2009 Global Financial Crisis all fit the pattern with remarkable precision).
The 11-year solar cycle is historically segmented into four distinct periods based on psychological excitability: Minimum (3 years), Growth (2 years), Maximum (3 years), and Decline (3 years).
» In each century, the universal cycle of historical events is repeated exactly 9 times. Throughout the world history of Mankind, beginning with 500 B.C. and until the present time, in each century I have discovered 9 clearly outlined concentrations of the initial moments of historical events. Thus, it can be considered that each cycle of the general historical, military or social activity of humanity is equal, on average, to 11 years. «
Valkov's long-term charts overlaying sunspot numbers with unemployment or industrial production in the US, UK, Russia, and China reveal an almost eerie synchronization that persists through wars, pandemics, gold standards, fiat currencies, and radically different political systems. Given that Solar Cycle 25 reached a stronger-than-expected maximum around 2024–2025, the HELI index indicates that the current global expansion has already peaked or is in its final stage.
» On average, the difference between the peaks and troughs of solar activity and economic cycles does not exceed six months. «
88% of recessions since the 1800s and 100% of major financial crises occurred during the downturn of sunspot cycles.
The model forecasts an accelerating contraction phase leading into a major multicycle trough centered on the early 2030s—precisely the period when the next solar minimum is expected. Mainstream macroeconomics remains deeply skeptical of any strong exogenous pacemaker for business cycles, and critics will rightly point to risks of overfitting and the indirect nature of causal mechanisms.
Yet, the sheer scope of the evidence—280 years, twelve diverse economies, consistent performance across radically different institutional regimes—makes the paper impossible to dismiss lightly. Whether helioeconomics ultimately gains broad acceptance or remains a heterodox curiosity, the HELI index has already demonstrated superior long-range forecasting ability compared with traditional indicators.
S&P 500 vs. Ap Index (Apr-Oct 2026). Projected Ap peaks: Sep 4 (Fri), Sep 17–20 (Thu-Sun), Oct 1 (Thu). The chart overlays daily S&P 500 candles with Ap shifted forward by three calendar days—the short lag that currently best balances the classic weekly effect reported in the literature with practical trading-day alignment—then extends the series with the NOAA 45-day Ap outlook. Daily Ap comes from GFZ Potsdam; the dashed forward segment is the latest NOAA SWPC 45-day Ap forecast issued August 22, 2026. 
