* If you decompose market behavior into a linear, trend component and one or more cyclical components, you can identify optimal time horizons for holding positions. Those optimal horizons are much longer than traders and portfolio managers typically hold. Most people hold positions for shorter-than-optimal periods because of such factors as the need to trade, the fear of losing money, overly tight risk management, etc. * Trends and cycles become more regular and noticeable when measured in event time, as opposed to chronological time. A simple example of event time would be bars denominated in volume rather than minutes, hours, days, or weeks. When assessing long-term cycles, the key is finding a way to measure event time given the variability of volume across instruments, across decades. Such event cycles are least stable over short time horizons; much more stable over longer horizons, per the first point above. * Who is in the mark...