Sunspots and Stocks - The Short-Term

Everything in the universe is constantly bathing in fluctuating electro-magnetic forces and fields that affect virtually every circuit in biological systems. Human physiological rhythms and global behaviors are not only synchronized with solar and geomagnetic activity, but disruptions in these fields can also create adverse effects on human health and behavior. Changes in geomagnetic activity are correlated with altered blood pressure, heart rate, melatonin levels, and increased occurrence of cancer, balance of hormonal system, reproductive system, cardiac and neurological disease, hospital admissions and mortality, as well as depression, fatigue, mental confusion, and traffic accidents. 

'Daily Sunspot Numbers' and 'F10.7 Flux' e.g. @ NASA's OMNIWeb

An important finding is that of all the bodily systems studied thus far, changes in solar activity and consequently geomagnetic conditions most strongly affect the rhythms of the heart. Of course electromagnetic fields generated by power supply systems, telecommunications, appliances, computers and other technology are extremely powerful and have similar effects on organisms.

In the late 1990s Jeffrey Owen Katz and Donna McCormick examined the effects of sunspots especially on the S&P 500 and Minnesota Wheat. They developed several profitable trading strategies generating entries and exits based on solar activity alone. However, they concluded: "We personally do not believe solar influences directly determine the market. We do suspect that they act as triggers for events that are predisposed to occur, or as synchronizers of already-present market rhythms with similar periodicities." Well ...