You are not to take advantage of someone who is in a disadvantageous position. It is clear from this part of the Bible, with references to employers not withholding wages from a mere day laborer, that those in a position of strength over another must act differently and with restraint compared to those in equal positions. Contracts must be signed as an act of freewill, without coercion or else they don't count. If someone asks you for money, you may give it to them and it is legal. If they use deadly force when they ask, it is illegal.
Monopoly law is related.
It is assumed that the company with the monopoly position has a position of unusual strength over the competition and therefore must behave in a less competitive manner. The Talmud chronicles some of this discussion. There is a section in the Talmud in the part called Baba Batra that discusses legal barriers to entry, namely when is a business allowed to set up shop nearby another and take away someone's livelihood. This speaks to taking monopoly position into account . If, however, they offer the same goods more cheaply or provide goods or services of better quality, then they cannot be prevented from operating.