The day before the U.S. expanded its Treasury bond repurchase program, investors placed a record bet on long-term U.S. Treasury bond ETFs

On August 20th, Jin Shi Data reported that just one day before the U.S. Treasury unexpectedly announced an expansion of the long-term Treasury bond repurchase program, pushing the bond market up, one or more investors made a large purchase of an ETF highly sensitive to fluctuations in U.S. long-term Treasury yields on Tuesday. On that day, the PIMCO 25+Yr Zero Cpn US ETF, with a scale of $1.5 billion, attracted a record inflow of $123 million, and the trading volume surged to 5.2 million shares, nearly double the previous peak set in 2024. This ETF invests in so-called "Separate Trading of Registered Interest and Principal of Securities" (STRIPS), which are zero-coupon securities formed by separating the principal and interest payments of bonds, thus amplifying bets on the trend of U.S. long-term interest rates. The ETF rose 3.2% on Wednesday, marking the largest increase since November 2024. However, concerns over inflation and fiscal deficits have impacted long-term Treasury bonds, and this fund has accumulated a decline of 5.4% this year. The effective duration of the fund's bond holdings is approximately 28 years, meaning that for every 1 percentage point decrease in yield, its price will rise by about 28%