Market Open: Stocks Mixed, Bond Yields Fall On Treasury Action, Moderna Shares Pop 8/19/26

CNBC's market open update covers a mixed-to-higher tape with bond yields falling after the Treasury doubled longer-dated buyback operations. Moderna and Merck rallied on positive Phase 3 melanoma vaccine data, while Lowe's guided lower and Target raised its outlook. Commentary also flagged weak private demand signals in long-dated Treasuries and rising fuel costs. - Major averages opened higher, with the Dow helped by Merck strength. - Treasury doubled liquidity buybacks for 10-30 year nominal coupons, pushing bond prices up and yields down. - Becky Quick warned the buybacks may signal weak private market liquidity and are not a great sign. - Moderna and Merck's Phase 3 melanoma vaccine data met primary and secondary endpoints. - Lowe's cut its full-year forecast on housing weakness; Target raised its outlook and received a tariff refund. - Oppenheimer's Rupesh Parikh sees Target in the middle innings of its turnaround with potential multiple expansion. - US crude oil traded above $85 and California diesel rose above $7, adding consumer inflation concerns. - US tariffs on Canadian goods were paused after a reported deal with Ottawa.