Over the past decade, I was continually asked by prospective clients at the beginning of every year what they should do with the cash they have been sitting on as they have been too afraid to get back into the market after the financial crisis. Year after year rolled by with sound returns missed by these individuals who sat on large cash positions. Their usual response was that they were "waiting for the right time to invest and for a 10% or 20% market sell-off to do so". Unfortunately for them, every time a ~ 10% market correction occurred they were still too afraid to get into the market as whatever event was currently occurring kept them from investing. Now that the stock market has sold off more than 20%, one would think investors would be clamoring to finally enter again. However, we know that isn't the case as more investors are currently selling than buying and individuals are again too afraid to purchase equities.
When an individual’s portfolio has reached a certain numerical value (i.e. $1 million, $2.5 million, $5 million, etc.), he tends to lock-in that valuation in his mind and is unwilling for it to move lower – at times even desiring to move to cash in order to preserve the valuation. If the market or his stock declines below the level in which he has locked-in the valuation, this can lead to irrational behavior driving the investor to sell his stocks at a lower valuation while also losing the dividend income from his investment.