On January 29, the US 50ETF (513850) staged a "sky and earth floor". The ETF opened at the limit price in the early trading session, then quickly fell, and in the afternoon it hit the limit down, with an intraday fluctuation of 20% and a premium rate of over 28%. On January 29, E Fund Management issued a risk warning and temporary suspension notice for the premium of the US 50ETF, marking the fifth consecutive trading day of risk warnings. Data shows that as of January 26, the US 50ETF had risen by 48.74% so far this year, with a premium rate as high as 42.46%. The ETF hit the limit up for three consecutive days on January 22, 23, and 24. Recently, the profit-making effect in A shares has been poor, while US stocks, Japanese stocks, and other markets have hit historical highs consecutively. Some secondary market funds have started to flow into cross-border ETF products, and as of January 26, the latest size of the US 50ETF has reached 139 million yuan. It is known that due to limited foreign exchange quotas, cross-border ETFs are prone to appearing in the secondary market due to insufficient supply of primary market fund shares, leading to a premium/discount phenomenon. To alleviate the high premium in the secondary market trading, E Fund has raised the daily cumulative purchase limit for three consecutive days, raising it from 3 million shares to 8 million on January 24, then to 20 million on January 25, and further to 50 million on January 26. Recently, Lin Weibin, general manager of the Index Investment Department of E Fund and fund manager of the US 50ETF, warned that since January 22, 2024, the trading activity in the secondary market of this fund has significantly increased, with trading prices significantly higher than the reference net asset value (IOPV) of the fund shares, posing a significant premium risk. Investors are urged to pay special attention to the premium risk of secondary market trading prices and make rational investment decisions. ETF products require tracking indexes with minimal tracking error. A high premium of up to 40% distorts the tracked index and deviates from the off-exchange fund's net asset value, posing a significant risk of speculative bubble. Some industry insiders advise investors not to blindly follow the trend, as once the market demand for this ETF decreases, the market price of the ETF may quickly decline, leading to losses for investors. In addition, some brokers believe that after the continuous decline in the previous period, the risks in A shares have been effectively released, and investment value has emerged. Investors should aim to make profits within their cognitive abilities. With the recent rapid changes and instability in the international situation, investors should not excessively speculate on overseas markets.