Consumer behavior varies under any kinds of conditions, including in uncertain situations. There is no one type of behavior that would cover all behavior patterns at any time.
If consumers are uncertain about the possible return they may receive from an investment due to conditions surrounding the investment, they may be reluctant to make any investment at all. Some might take a risk and invest some money, but possibly not as large an amount as they would have invested if they had felt more confident about the situation. Shoppers may reduce their purchases of new products during periods of financial uncertainty and may spend much more time evaluating and comparison-shopping before buying.
If stockholders are unsure of what the stock market trends might mean for the future, they may be inclined to reevaluate their holdings but will not all take the same steps as a result of the reassessment. Some may choose to sell some or all of their stocks, hoping to reap a profit before the price of their shares declines. Some might buy more stock, feeling that the cost per share is about to increase greatly.