One of the most common mistakes that investors make when it comes to margin calls is not understanding the risks associated with using margin. Many investors may not fully comprehend the potential for significant losses if their investments decline in value. Additionally, some investors may overestimate their ability to cover margin calls, assuming that they will be able to liquidate assets or obtain additional funds quickly. Another common mistake is not maintaining sufficient margin in their accounts, leaving them vulnerable to margin calls if the market turns against their positions. Finally, some investors may become too aggressive with their margin investments, taking on too much risk and increasing the likelihood of margin calls.