Tuesday’s session on Wall Street and in Europe was a study in contradictions: indices closed within a whisker of record highs as oil sank on Iran ceasefire optimism — yet the session left behind a cybersecurity wreckage and an earnings-season subplot, before US strikes in the Strait of Hormuz overnight reset the risk calculus entirely for Wednesday’s open.
For investors in Asia and Korea waking on May 28, the picture has shifted considerably from where US markets left off at 4 PM ET.
US Markets: Flat Close Masks a Turbulent Session
All three major US indices closed May 27 with modest gains that belied the day’s underlying volatility:
- S&P 500: 7,520.36 (+0.02%) — essentially unchanged. (Yahoo Finance)
- Dow Jones Industrial Average: 50,644.28 (+0.36% / +182.60 pts), recovering from a prior close of 50,461.68. Intraday high: 50,830.41. (Yahoo Finance)
- Nasdaq Composite: 26,674.73 (+0.07%), ranging between 26,538.31 and 26,715.31. (Yahoo Finance)
The flat aggregate numbers concealed two starkly different earnings stories playing out beneath the surface.
Zscaler: A 31% Single-Day Collapse
Cybersecurity firm Zscaler (ZS) was the session’s most dramatic casualty, plunging 31.52% to close at $126.41 — a loss of $58.19 per share. The collapse made it the market’s worst performer on the day, with investors reacting to earnings results that fell short of elevated expectations. (Yahoo Finance: ZS)
The ZS selloff dragged on the broader cybersecurity sector and added to a list of high-profile post-earnings declines that has characterized this earnings season. PDD Holdings also fell 10.38% on the day. (Yahoo Finance: PDD)
Salesforce: Beat on Revenue and EPS, But Q2 Guidance Disappoints
Salesforce (CRM) reported Q1 FY2027 earnings after the bell on May 27, delivering a notable beat across most metrics: revenue of $11.13 billion (+13% year-over-year) and adjusted EPS of $3.88, well above the $3.13 consensus estimate. However, the Q2 revenue outlook came in slightly below expectations, raising questions about whether AI-driven momentum is converting to guidance, according to Proactive via Yahoo Finance.
CRM closed the regular session at $177.51 (-0.88%), and fell a further 1.23% in pre-market trading on May 28 to $175.43. Agentforce AI adoption was cited as the growth engine, but investors remained focused on near-term guidance. (Yahoo Finance: CRM)
NVIDIA (NVDA) continued to trade under modest pressure, sliding 1.05% to $212.60, as the AI-chip trade shows signs of digestion after months of strong gains. (Yahoo Finance: NVDA)
European Markets: Mixed Session, BP Hit by Sudden Chairman Exit
European equities closed mixed on Tuesday, caught between Iran peace optimism that sank oil prices and fresh uncertainty about whether those talks would hold.
According to a PA Media report via Yahoo Finance, the FTSE 100 edged up during the session as oil prices sank — since lower crude is a net positive for import-heavy European economies — before ultimately closing at 10,505.01, marginally below the prior session’s 10,518.61. Headlines also described the day as “European Stocks Close Mixed Tuesday Amid Renewed Strains in US-Iran Talks.” (Yahoo Finance: ^FTSE)
The UK-specific story of the day was BP, which was knocked by the sudden resignation of its chairman, making it the standout underperformer in London even as broader UK stocks climbed, per PA Media via Yahoo Finance.
Defence stocks were highlighted among May 27’s European gainers, as the geopolitical backdrop continued to support defence spending themes across the continent. (Proactive via Yahoo Finance)
Macro: Oil, the Fed, and Overnight Escalation
Oil Sank During the Day — Then Surged Overnight
Brent crude declined during the May 27 session as markets priced in optimism surrounding ongoing US-Iran ceasefire negotiations in Doha. However, the picture shifted entirely overnight. By May 28 early morning (Asia time), Brent had rebounded to $94.67 per barrel (+2.62%) after reports of fresh US military strikes in the Strait of Hormuz zone circulated, reigniting supply-disruption fears. (Yahoo Finance: BZ=F)
The headline from the Yahoo Finance live market blog: “Dow, S&P 500, Nasdaq futures drop following US strikes in Hormuz.”
Treasury Yields and a New Fed Chair Under Pressure
The 30-year US Treasury yield held at 5.01% — an elevated level that continues to weigh on rate-sensitive equities. (Yahoo Finance: ^TYX)
New Federal Reserve Chair Kevin Warsh, who was sworn in last Friday, faces what analysts are calling a “dual price shock” — geopolitical energy inflation from the Middle East conflict on one hand, and tariff-driven goods price pressures on the other. A Motley Fool analysis via Yahoo Finance noted that Warsh “yearns for central bank reform” but faces immediate structural constraints that limit his policy flexibility.
April PCE inflation data is due later this week and will be closely watched as a signal for whether rate cuts remain on the table in 2026. Follow the release timing on the Economic Calendar.
VIX and Sentiment
The CBOE Volatility Index (VIX) rose to 16.74 (+2.76%) on May 28 morning, reflecting rising near-term uncertainty as overnight developments in the Strait of Hormuz put markets on edge after a relatively calm US session. (Yahoo Finance: ^VIX)
What Asian and Korean Investors Should Watch on May 28
- US Futures in the Red: As of early May 28, S&P 500 futures are at 7,521.25 (−0.25%), Nasdaq 100 futures −0.49%, and Dow futures −0.19%. A gap-down open on Wall Street is likely as markets digest the Hormuz strikes. (Yahoo Finance)
- Oil Back Above $94: Brent’s 2.6% overnight surge after US strikes reverses the prior session’s optimism. Watch energy and shipping-related names in Korea and Japan carefully.
- Salesforce Q2 Guidance in Focus: The slightly-below-consensus Q2 outlook from Salesforce is a bellwether for enterprise software demand and AI monetization. Korean tech investors watching global SaaS sentiment should note that the AI trade is increasingly about execution, not just narrative.
- April PCE Data: Due this week. A higher-than-expected print could cement the “no rate cut in 2026” view, with implications for bond markets and equity valuations globally. Check the Economic Calendar for the exact release time.
- KOSPI at 8,000: After Tuesday’s record, Korea’s benchmark faces its first real external stress test. Track the KOSPI as futures direction and oil movement collide.
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Sources
- Yahoo Finance — S&P 500 (^GSPC)
- Yahoo Finance — Dow Jones Industrial Average (^DJI)
- Yahoo Finance — NASDAQ Composite (^IXIC)
- Yahoo Finance — FTSE 100 (^FTSE)
- Yahoo Finance / Proactive — “Salesforce beats on every metric but the existential AI question lingers”
- Yahoo Finance live blog — “Dow, S&P 500, Nasdaq futures drop following US strikes in Hormuz”
- PA Media / Yahoo Finance — “FTSE 100 edges up and oil sinks amid peace optimism”
- PA Media / Yahoo Finance — “Stocks climb but BP knocked by chairman’s sudden exit”
- Motley Fool / Yahoo Finance — “New Fed Chair Kevin Warsh Yearns for Central Bank Reform”