1) Uncertainty is always subjective. It is a state of mind that is derived from a mix of objective data, emotions and personal experience. To say that the market is always equally uncertain is to say that mood is always the same. It is not. It constantly changes.
If the perceived uncertainty is always the same, earnings reports would not have such huge impact on prices. We all know that this is not the case. In many cases, earnings reports provide new data that changes market expectations and therefore prices. Options premium is higher before earnings exactly because uncertainty is higher.
2) Uncertainty has become a synonym for bad mood in our everyday life.
The future is always uncertain, but our perceptions of the future vary. And perceptions define actions. Actions (supply and demand) define prices. Somehow uncertainty is used with a highly negative connotation in our everyday life. It is a game of words. Just like the weather people always say that there is a 30% chance of rain and never that there is 70% chance of sun.
3) Uncertainty is basically another word for market sentiment. High levels of perceived uncertainty (bad mood) and high levels of perceived certainty (good mood) have historically been good contrarian indicators, IF your investing horizon is long enough.
4) There are different types of uncertainty.
There is an economic uncertainty. Uncertainty leads to a decline in economic activity. Less people are hired. Old machines and software licences are used longer. Investments are cut. This is what it has been happening in Europe for 2 years.
Everybody is bullish on gold these days. You even have outfits like ‘Cash For Gold’ peddling their trades at your local mall. But historically, gold has never been a great long term investment.