[BlackRock iShares Preferred and Income Securities ETF Discloses Holding Strategy Stocks Worth $471 Million] According to BitcoinTreasuries.NET, BlackRock iShares Preferred and Income Securities ETF has just disclosed its holdings of Strategy's STRC, STRF, STRK, and STRD stocks, valued at $471 million, accounting for 3.3% of the ETF's total size.