IEF gained 1.08% and TLT 1.87% as the 10-year Treasury yield fell over 17 basis points to 4.972%, its lowest since Sept. 23. Equity weakness, AI credit concerns, and safe-haven demand supported bonds, though oil near $100 keeps inflation risks alive. Bulls favor TLT if growth cools; bears warn long duration is vulnerable to inflation and rate repricing. What macro signal would justify extending duration from IEF to TLT?