If you'll forgive the discourse (and at the risk of wandering a bit afield), over the years I've found thinking about the world from the standpoint of seeds to be enormously helpful. My friend Thich Nhat Hanh puts it this way:
“Consciousness is said to be a field; a plot of land in which every kind of seed has been planted – seeds of suffering, happiness, joy, sorrow, fear, anger, and hope. The quality of our life depends on which of these seeds we water. The practice of mindfulness is to recognize each seed as it sprouts, and to water the most wholesome seeds whenever possible.”
The basic idea is that, confronted with a whole host of seeds in our daily lives, the ones that we water will generally (though not always) be the ones that grow. So if we tend and water the negative seeds; worry, anger, disappointment, fear, and so on, the energy we put toward those seeds will tend to make them grow and become very big in our daily lives. If instead we tend and water the positive seeds; friendship, gratitude, discipline, peace, and happiness, then those are the seeds that will grow. That doesn't mean walking around like a Polyanna (which is unlikely for a crusty skeptic like me), but it does mean that there is some tendency, however imperfect, to reap what we sow, even just by what we choose to habitually think about. As the Buddha said, “with our thoughts, we create our world.”
Seeds not planted or tended by choice tend to be weeds, so at least for me, it's very helpful to consciously and periodically choose which seeds I want to water, and to think through what I expect to happen from that watering. Investors can spend a lot of time and energy reacting to the latest bits of news and trying to predict the next surprise, rather than choosing a consistent set of daily actions that they can carry out as things develop, regardless of how they develop.