4 กับดัก ETF ที่นักลงทุนส่วนใหญ่เจ๊งเงียบโดยไม่รู้ตัว! | NEW GEN INVESTOR (HL)

When choosing ETFs, investors must understand that not all ETFs offer the same level of diversification. For example, the XLV healthcare fund holds over 60 stocks, but its top 10 holdings account for nearly 60% of the portfolio, making it concentrated. In contrast, another healthcare ETF with 410 stocks covers large, medium, and small companies, with its top 10 holdings making up only about 50% of the total weight. This highlights that some ETFs are "High Conviction" with high individual stock weightings, while others are truly diversified across hundreds or thousands of stocks. Investors should choose based on their risk tolerance and ability to absorb returns, considering if they prefer scattered or clustered investments. Another pitfall is "overlap teeth," where investors unknowingly buy multiple ETFs or funds that contain many of the same underlying stocks. For instance, purchasing both QQQ (US tech stocks) and VGT (technology-focused ETF) results in significant overlap, as QQQ's top holdings like Nvidia, Apple, and Microsoft are also prominent in VGT. If an investor owns VTI and then buys QQQ, 93% of QQQ's stocks might already be in VTI. This overlapping means buying multiple ETFs doesn't automatically diversify risk as effectively as intended. Furthermore, while ETFs offer diversification and low fees, they are still risky assets. The belief that they are "risk-free" due to diversification can lead to panic selling during market downturns. Although long-term investment generally smooths out volatility, investors should manage their money broadly, ensuring sufficient emergency funds and assessing their capacity to handle crises. Finally, investors should not rely heavily on past performance as a guarantee of future results. While historical data can inform decisions, past returns do not ensure future success. Long-term averages (10-20 years) provide a more realistic view of an ETF's performance and volatility.