It seems to me looking at a stock price chart, where time is the X axis, can be intuitively misleading... because the lizard part of our brain starts seeing patterns that shouldn't exist. It's extremely tempting to start assuming physical forces: "falling" (as in gravity), "momentum". I think it may be more insightful looking at a chart where time is the Y axis. The stock chart is crawling down, swinging left/right. To me, it'd look more like a stream flowing down hill... and that's probably a more appropriate description of the random process behind the movements.