Summit Therapeutics Inc. (SMMT) shares tumbled 5.3% to $16.90 as of September 22, 2026, a significant decline from the prior close of $17.85. BestStocks flagged the session as a major change for SMMT. Below, we break down what changed for SMMT, why it matters for investors, how the stock reacted, and the catalysts on the calendar.
What happened
SMMT fell 5.3% to $16.90
SMMT tumbled 5.3% in its latest session, moving from $17.85 to $16.90.
ValuationLow confidence
Rel. volume
1.1×
Normal
Vs peers
—
No comparable peers
Market cap
$13.5B
NASDAQ Global Market
Analyst target
$27
+58.9% vs price
Price chart
Aug 24 – Sep 22
E earnings
F filing
A analyst
V/N other
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Change events — click to jump to details
What it means for Summit Therapeutics Inc. investors
For Summit Therapeutics Inc. investors, the recent signals add up to a bearish shift. On the constructive side: Summit Therapeutics Inc. (SMMT) moved +8.37% from $13.50 to $14.63 on 2026-07-21; Summit Therapeutics Inc. (SMMT) moved +7.23% from $14.38 to $15.42 on 2026-07-02. Weighing against that: Sharp 5.3% decline — elevated risk; Summit Therapeutics Inc. moved -10.08% intraday from $14.98 to $13.47. Wall Street's consensus price target sits at $26.86, implying +58.9% upside from $16.90. Over the past 90 days analysts logged 3 upgrades and 0 downgrades. BestStocks rates the overall signal quality low (59/100). With earnings roughly 27 days out, the next report is the most likely near-term test of the move.
SMMT price reaction
SMMT last traded at $16.90, down $0.95 (-5.32%) from the previous close of $17.85. The session traded on 1.1× average volume (normal), so participation was unremarkable. Over the past month the stock has ranged between $12.73 and $18.42, and it currently sits about 73% of the way up that band.
Bullish and bearish analyst opinions on Summit Therapeutics Inc. (SMMT)
The consensus analyst price target on Summit Therapeutics Inc. (SMMT) is $26.86, 58.9% above the recent $16.90. Over the past 90 days analysts logged 3 upgrades, 5 maintains, and 0 downgrades. Here is how the bullish and bearish cases on SMMT line up.
▲ The bullish case
+Wall Street's consensus price target of $26.86 implies +58.9% upside from $16.90.
+The Street's most bullish target is $38.00 (+124.9%).
+3 analyst upgrades in the past 90 days, most recently Jefferies to Buy (2026-09-09).
+Summit Therapeutics Inc. (SMMT) moved +8.37% from $13.50 to $14.63 on 2026-07-21.
▼ The bearish case
−The most bearish analyst target is $15.00 (-11.2%).
−Sharp 5.3% decline — elevated risk.
−Summit Therapeutics Inc. moved -10.08% intraday from $14.98 to $13.47.
Bull vs bear balanceBearish Shift
BearishNeutralBullish
Weighing both sides, BestStocks' composite read of recent signals is bearish, as the bull-versus-bear meter above shows. This is an educational summary of the bull and bear case, not investment advice.
Analyst price targets and ratings are FMP consensus figures as of Sep 22, 2026; other aggregators may differ. High and low targets show the range of estimates, not forecasts.
Summit Therapeutics gained 4.59% to $18.36 following positive overall survival data for its flagship cancer drug ivonescimab in the HARMONi-2 trial, where partner Akeso reported the treatment demonstrated statistically significant benefit versus Merck's Keytruda in advanced non-small cell lung cancer patients (investors.com). Analyst upgrades, including a recent Buy rating from Jefferies with raised price targets, have also bolstered investor confidence ahead of the FDA's November 14, 2026 target action date. Volume at 5.16M shares remains normal for session timing.
Summit Therapeutics shares rose 3.71% to $17.63 following a Jefferies analyst upgrade to Buy with a price target raised to $25, combined with positive overall-survival data for its flagship lung cancer drug ivonescimab reported by partner Akeso (per finance.yahoo.com). Volume of 1.72M shares ran 0.40x the expected intraday average, suggesting contained retail participation.
Summit Therapeutics rose 12.47% to $16.42 on renewed investor interest surrounding positive Phase III results for its lead drug ivonescimab, according to Yahoo Finance reporting from 17 hours ago. Volume reached 4.8 million shares (3.36x the time-adjusted average), underscoring elevated retail and institutional participation. The stock has gained 24% over three months driven by ivonescimab progress and FDA acceptance of the BLA, per Zacks.
Material / Earnings2026-09-01+4.0%
Summit Therapeutics Inc. (SMMT) moved +5.83% from $13.38 to $14.16 on September 1, 2026, following publication of primary analysis results from the Phase III HARMONi trial for ivonescimab in *The Lancet Oncology*. The peer-reviewed data demonstrated significant progression-free survival benefits for ivonescimab combined with chemotherapy.
Summit Therapeutics rose 11.53% to $14.90 following a Bernstein analyst upgrade and positive momentum around its ivonescimab program. According to the web catalyst, the upgrade boosted near-term sentiment, while recent Phase III HARMOni trial data publications in *The Lancet Oncology* regarding the bispecific antibody continue to attract investor attention.
Summit Therapeutics (SMMT) fell 4.93% to $13.31 on August 14, 2026, driven by a combination of a wider-than-expected Q2 net loss ($0.28 per share versus $0.26 consensus), recent institutional share offloading by major holders such as Dimensional Fund Advisors, and persistent investor caution over overall survival data requirements for its lead cancer drug ivonescimab (per finance.yahoo.com). Volume elevated at 2.81x the historical average for this time of session.
Material / Earnings2026-08-13-7.3%
Summit Therapeutics Inc. (SMMT) moved -7.35% from $15.11 to $14.00 on 2026-08-13. We checked news, earnings, analyst updates, filings, and corporate actions. While no single discrete catalyst was identified, the decline occurs amid ongoing investor re-evaluation of ivonescimab's clinical data maturity, regulatory timeline, and recent cautious analyst sentiment including price target trims from Wall Street firms. Volume was 1.9x the 5-day average—modestly elevated.
Material / Earnings2026-08-10+6.5%
Summit Therapeutics Inc. (SMMT) moved +5.20% from $14.13 to $14.87 on 2026-08-10. We checked news, earnings announcements, analyst updates, SEC filings, and corporate actions — no company-specific catalyst was found. Volume remained near its 5-day average at 1.1x.
In-depth SMMT event analyses
Permanent, dated analyses of SMMT's most significant sessions.
Why did Summit Therapeutics Inc. (SMMT) stock move?
SMMT tumbled 5.3% to $16.90. No single company-specific catalyst was confirmed during the move window, and it looks technical.
How much did SMMT stock fall?
SMMT lost 5.32% ($0.95) versus the prior close of $17.85, last trading at $16.90 on 1.1× average volume.
When is Summit Therapeutics Inc.'s next earnings date?
SMMT's next earnings report is estimated for 2026-10-19 — about 27 days away.
What is the analyst price target for SMMT?
The consensus analyst price target for SMMT is $26.86, about 58.9% above the current $16.90. Over the past 90 days, analysts recorded 3 upgrades, 5 maintains, and 0 downgrades.
How BestStocks tracks SMMT
This page is generated automatically by BestStocks' change-detection system after its price and volume cleared SMMT-specific materiality thresholds, triggering an evidence check. It draws on 20 tracked change events for SMMT, cross-checked against the data sources listed below. Price, volume, and market-capitalization figures are the live intraday quote as of September 22, 2026 and refresh as new information is detected; for companies with multiple share classes, market-cap figures can differ by data source. Analyst price targets and ratings are FMP consensus. This is an educational summary of what changed and why — not personalized investment advice.
