According to Warren Buffett, as cited by @WarrenBuffett on Twitter, investors should only buy stocks if they fully understand the underlying business, emphasizing the importance of staying within one's circle of competence. For crypto traders, this principle translates to thoroughly researching blockchain projects and digital assets before investing. Understanding tokenomics, team background, and utility can help avoid high-risk positions and improve portfolio performance in volatile markets (Source: @WarrenBuffett).