A turbulent trading week ending August 21 delivered historic moves across stocks, bonds, crypto, and biotech sectors simultaneously.
Treasury Secretary Scott Bessent made a rare and dramatic intervention Wednesday after the 30-year Treasury yield hit 5.27%, a 19-year high.
The surge in long-end yields was driven by concerns over the $40 trillion national debt, a fiscal 2026 deficit tracking above $1.8 trillion, and heavy AI-related corporate bond issuance.
Two weeks after publishing its buyback schedule, the Treasury announced it would “at least double” its purchases of 10- to 30-year debt to stabilize markets.
The announcement immediately pushed yields lower, with the 30-year dropping nine basis points and the 10-year falling 5.7 basis points on the news.
The relief proved short-lived, however, as the 30-year yield climbed back to 5.25% by Friday, nearly erasing the intervention’s impact within 48 hours.
On August 19, Moderna and Merck announced a positive Phase 3 INTerpath-001 result for their personalized mRNA cancer vaccine, intismeran, in high-risk resected melanoma.
The therapy met its primary endpoint of improved recurrence-free survival and a key secondary endpoint of distant metastasis-free survival, marking the first successful late-stage readout for an mRNA cancer vaccine.
MRNA shares surged more than 177% that day in what the company recorded as the biggest single-day rally in its history.
Short sellers absorbed roughly $5.5 billion in losses as the stock exploded higher, before shares gave back 20% Thursday on profit-taking, then rebounded 11.5% Friday.
Walmart (WMT), the nation’s largest grocer, was punished despite reporting an earnings beat, with shares sliding roughly 11% and putting the retailer on track for its worst week since 2022.
Bitcoin posted its best weekly performance since February 2023, with the digital currency on pace to end the week more than 20% higher as crypto sentiment surged broadly.
Crypto-related stocks rose sharply alongside Bitcoin, with Robinhood, Coinbase, and Strategy each climbing at least 4.5% in premarket trading on Friday.
The Treasury also raised the maximum per-operation buyback size from $2 billion to at least $4 billion for the 10-to-20-year and 20-to-30-year sectors, effective September 9 through November 4.
Major indexes were nonetheless poised to register weekly declines for the first time since late July, even as stocks ticked higher in early Friday trading with oil little changed and yields temporarily stabilized.
