Surge in Short Interest Hits iShares Paris-Aligned Climate MSCI USA ETF Short interest in the iShares Paris-Aligned Climate MSCI USA ETF (PABU) soared 323% in March, reaching over 70,000 shares. Despite this, the ETF's price has shown resilience, recently trading near $58. Market participants are closely watching for further volatility as sustainability-focused funds face shifting investor sentiment.12