The YouTube transcript argues that professional poker players excel as financial traders because both activities are fundamentally games of incomplete information rather than mere games of chance like roulette or lotteries. The speaker explains that in games of chance, the player has a fixed negative edge or expected value, ensuring long-term losses, while games of incomplete information, such as poker and trading, allow a player's optimal action to influence the expected value of each decision. Success in both fields stems from learning and iteratively refining an optimal policy function through experience, which enables the player or trader to accumulate wealth by acting with a positive expected value or by taking expected value from less-skilled participants in what is often a zero-sum game. Effective risk management and the ability to avoid emotionally driven decisions, such as "being on tilt," are also highlighted as critical components of maximizing long-term performance in both poker and trading