Greed and emotions can lead to big losses in forex trading if they are not properly controlled. Traders who become overly attached to a trade or allow their emotions to drive their decisions are more likely to make impulsive and irrational choices. This can lead to taking on too much risk, ignoring stop-loss orders, or failing to take profits when they should. Similarly, traders who become overly greedy and take on more risk than they can handle may experience big losses when the market turns against them. It is essential to maintain a level head, follow a solid trading plan, and use risk management strategies to keep emotions and greed in check.