It is the nature of the Pentacles suit - and indeed, the nature of the human being - to favor tradition and be apprehensive of change. After all, change can upset the security and balance that we are taught to achieve, and once we have found success, shouldn't we try to keep it? Such a philosophy has led to many people staying successful, but it has also led to others losing everything they hoped to preserve. To try and fight change is a task which ultimately proves futile. The fear of loss may certainly prevent loss, but it also prevents further gain.
The Four of Pentacles can show times of material security and happiness, and it often marks a time of financial gain, either earned through work or simply acquired from another source, such as inheritance. It is a card of earthly power, but with no accompanying emotional or spiritual gain. This is where its meaning starts to take a more negative turn. Without the wisdom to help you manage your material assets, you will either squander them or start to hoard them. Both will lead to frustration and disappointment. Power without the knowledge to use that power frequently harms the user.
This is the card of the miser, and it shows us all the effects of greed and selfishness. The miser refuses to help others who are in need, because there is a risk that he would lose some of his hard-earned money. Thus he loses a lot of the people whom he considered friends. As a miser you stop having fun because you are constantly preoccupied with how much "fun" will cost. Your foundations may be stable, but you can never be comfortable if your home is a fortress and you spend every waking moment trying to defend it. And sooner or later, despite your efforts, change will strike and you will be humbled.
This card often embodies holding on, to money, to posessions or even to other people. In the majority of cases, one thing that the Four of Pentacles tells us is that we have to let go. By letting go of greed and selfishness you may lose a bit of your money, but the gain in terms of happiness will outweigh any material loss. Sometimes you may find that you are clinging to the past just as the man on this card clings to his coins, and if so, the appearance of the Four of Pentacles should be taken as a sign to put your past behind you. Even if you think the past was better than the present, you must not cling to it or use it as a security blanket.