nav, we will see spike tops and rounding bottoms in individual equities as well as commodities. part of that is the sensitivity to fundamentals of the vehicle examined. stock indexes show the summed cyclic action of their underlying components, thus a smoothing of price action based on individual component fundamentals occurs. in some "commodities" such as foreign currencies, we often see the rounding tops and V lows in the dollar and the inverse in the currency traded against it. many commodities also are much more subject to specific fundamental events of a short term nature particular to them. crop reports, weather, etc.
fundamentals do play an important role in price action. as Hurst described what he called the "price motion model". 75% of price action was forseeable fundamental events, long term, smooth, and trend like in nature. 2% was unforeseeable fundamental events that add specific randomness to price motion.the rate of occurrence is small but the effect can be large and sudden. 23% of of all price motion is oscillatory, complex but semi predictable. (cyclic price action).
Thanks.