The hottest ETF trims its Samsung holdings and buys into ChangXin. This week, U.S. ETF management firm Roundhill made significant adjustments to its DRAM-themed fund, reducing its stake in Samsung Electronics while simultaneously purchasing shares of ChangXin Memory. This marks the first time China's memory leader has entered a mainstream U.S. DRAM investment product. On Tuesday and Wednesday, Roundhill accumulated a total of 65 million shares of ChangXin Memory, quickly raising its weight in the DRAM ETF to 2.47%. Meanwhile, from Monday to Wednesday, Roundhill sold approximately 1 million shares of Samsung Electronics daily, totaling 3 million shares over three days.