S&P 500 futures flat as a Phase 3 vaccine result offsets a 5.80% Kospi fall
Sentiment: mixed S&P 500 futures: +0.03% | Nasdaq futures: -0.05% | Dow futures: +0.12%
S&P 500 futures traded at 7,716.50 at 08:40 ET on 19 August 2026, up 0.03%, a flat print that nets a first-in-class cancer vaccine result against a Seoul session that tripped its circuit breaker. Moderna MRNA.US traded 91.10% higher before the bell after intismeran autogene plus Keytruda met both endpoints in the Phase 3 INTerpath-001 melanoma trial, and co-developer Merck MRK.US gained 7.20%. The 30-year Treasury yield eased to 5.27% from Tuesday's 5.33%, its highest since 2007 and the level that drove the S&P 500 down 0.69% in the prior session.
Overnight drivers
- MRNA.US +91.10% to $120.31 pre-market. Intismeran autogene with Keytruda met recurrence-free survival and distant metastasis-free survival endpoints across 1,137 patients with resected stage IIB to IV melanoma, the first positive Phase 3 for an individualized neoantigen therapy. MRK.US +7.20% to $144.90, and Merck sits in the Dow, which is why Dow futures lead the three at +0.12%.
- KOSPI -5.80% to 6,471.17, where the Korea Exchange triggered a sidecar to suspend program sell orders. SK Hynix closed 9.75% lower in Seoul and Samsung Electronics 7.82% lower. The index now sits 31.05% below its 9,385.59 high.
- SK Hynix committed 40 trillion won, about $29 billion, to repurchase and cancel up to 24 million shares between 20 August and 19 November, the largest treasury cancellation by a Korean listed company. SKHY.US +4.96% pre-market and EWY.US +4.57%, both moving against the Seoul close.
- 30-year Treasury 5.27%, down 2 bp; 10-year 4.68%, down 3 bp. The long end reversed after Tuesday's 5.33% print, which landed alongside US debt approaching $40 trillion and July's largest monthly federal deficit since March 2021.
Overnight Asia and Europe
- KOSPI: 6,471.17 (-5.80%)
- Nikkei 225: 65,326.42 (-3.16%)
- Shanghai Composite: 3,894.42 (-2.40%)
- Hang Seng: 25,495.07 (+0.09%)
- STOXX 600: 652.12 (+0.03%)
- DAX: 26,093.51 (-0.13%)
- FTSE 100: 10,722.17 (-0.05%)
Seoul and Tokyo memory names followed Tuesday's US session lower, where SNDK.US fell 9.01%, STX.US 9.16%, WDC.US 7.43% and MU.US 7.02%. Europe did not follow. The STOXX 600, DAX and FTSE 100 all sit inside 0.15% of Tuesday's close at 08:40 ET.
US pre-market movers
| Ticker | Pre-market | Catalyst |
|---|---|---|
| MRNA.US | +91.10% | Phase 3 melanoma vaccine met both endpoints |
| MRVL.US | +11.94% | Expanded Google custom silicon deal, warrant issued |
| MRK.US | +7.20% | Co-developer of the same melanoma vaccine |
| SKHY.US | +4.96% | 40 trillion won buyback and share cancellation |
| SNDK.US | +3.48% | Rebound from Tuesday's 9.01% fall |
| ADI.US | +1.96% | Record fiscal Q3, outlook above consensus |
| TJX.US | -5.27% | Beat and raised FY27 guidance, shares still lower |
| AVGO.US | -4.49% | Fell in the same minute as the Marvell Google filing |
| LOW.US | -2.44% | Q2 beat, outlook trimmed on DIY spending |
MRVL.US and AVGO.US moved in opposite directions inside the same 08:25 ET minute, MRVL.US from $214.00 to $236.25 and AVGO.US from $380.27 to $367.00.
Marvell and Google
Marvell disclosed in an SEC filing that it expanded its partnership with Google on 29 July 2026 across custom silicon attached to the TPU ecosystem, covering AI inference accelerators, storage controllers, network interface controllers, memory interface controllers and near-memory compute. Marvell issued Google a warrant on 18 August over as many as 58.97 million shares at an exercise price of $206.58, about 6.7% of its 875.77 million shares outstanding.
About 1.36 million of those shares vest in equal quarterly instalments across the first year. The rest vest in 240 tranches, one for each $500 million of Custom Products revenue booked from fiscal Q3 2027 through fiscal 2033, which puts full vesting at $120 billion of that revenue. Broadcom has been Google's established TPU partner. GOOGL.US was little changed pre-market.
Retail earnings before the open
- TJX.US reported fiscal Q2 EPS of $1.22 against $1.19 consensus on revenue of $15.18 billion, comparable sales up 4%, and raised full-year FY27 pretax margin and EPS guidance. Shares -5.27% pre-market.
- LOW.US beat on Q2 and trimmed its outlook, citing pressure in DIY spending. Shares -2.44%.
- TGT.US posted sales up 5.3% and raised guidance, with tariff refunds inside the quarter doubling reported earnings. Shares +0.77%.
- ADI.US reported record fiscal Q3 results and an outlook above consensus. Shares +1.96%.
Macro and commodities
- 30-year Treasury: 5.27% (-2 bp)
- 10-year Treasury: 4.68% (-3 bp)
- US Dollar Index: 99.39 (-0.27%)
- Brent: US$91.42 (+0.44%)
- WTI: US$84.43 (+0.44%)
- Gold: US$4,424.50/oz (+0.09%)
- VIX: 15.65 (-1.20%)
Brent has held above US$90 since 17 August, when Iran ruled out extending the interim deal. Kpler counted three vessels crossing the Strait of Hormuz on Sunday against a five-day average of 12, and about 130 before the conflict began on 28 February. VIX sits at 15.65 after the S&P 500's third consecutive lower close.
US calendar today (ET)
- 2:00pm: FOMC minutes from the 28 to 29 July meeting, which held the funds rate at 3.50% to 3.75% with three dissents favouring a hike.
- Morning: EIA weekly crude inventories, with Brent above US$90.
- Before the open: TGT.US, LOW.US, TJX.US and ADI.US, all now reported.
What to watch
- FOMC minutes at 2:00pm ET cover a meeting that closed before July CPI and payrolls landed, with three voters on record for a hike.
- SKHY.US +4.96% pre-market against SK Hynix's 9.75% fall in Seoul, with the buyback window opening 20 August.
- SOXX.US +0.89% pre-market after falling 4.96% on Tuesday, against a KOSPI that fell 5.80% overnight.
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