Actual reversal to upside price action requires intervention by interested buyers.

Big and persistent buyers must overpower sellers to push stock's price higher

In any speculative market, a snowball that starts going downhill tends to keep going.

Prices swing emotionally from overvaluation to undervaluation. The extent of overshooting on each side is impossible to predict because it is driven by volatile emotions.

So an investor's first job is to become smart enough to realise that the market gyrates and then to get out of the way before the pendulum swings adversely.

While stocks do not always accelerate in decline as an easy telltale signal of having bnttomed, it is universally true that an actual reversal to upside price action requires intervention by interested buyers.

Such buyers must be big and persistent enough first to stop the price decline and then to stabilize the price against any trickle of further selling that results from boredom.

Finally, they must overpower sellers on an ongoing basis to push the stock's price higher.

With literally thousands of stocks available to buy, once a company becomes troubled in the collective opinion of the market, it will take considerable time and probably some notable events for improved prices to hold.