MKS Inc. (MKSI) shares tumbled 10.5% to $239.27 as of September 15, 2026, a sharp decline from the prior close of $267.31. BestStocks flagged the session as a major change for MKSI. Below, we break down what changed for MKSI, why it matters for investors, how the stock reacted, and the catalysts on the calendar.
What happened
MKSI fell 10.5% to $239.27
MKSI tumbled 10.5% in its latest session, moving from $267.31 to $239.27.
ValuationLow confidence
Rel. volume
0.8×
Below Avg
Vs peers
—
No comparable peers
Market cap
$16.2B
NASDAQ Global Select
Analyst target
$408
+70.6% vs price
Price chart
Aug 17 – Sep 14
E earnings
F filing
A analyst
V/N other
click a marker to highlight
Change events — click to jump to details
What it means for MKS Inc. investors
For MKS Inc. investors, the recent signals add up to a bearish shift. On the constructive side: MKS Inc. (MKSI) moved +6.53% from $324.28 to $345.44 on 2026-07-21; MKS Inc. (MKSI) moved +5.55% from $349.39 to $368.78 on 2026-07-09. Weighing against that: Sharp 10.5% decline — elevated risk; MKS Inc. (MKSI) moved -4.12% from $304.92 to $292.35 on 2026-08-10. Wall Street's consensus price target sits at $408.14, implying +70.6% upside from $239.27. BestStocks rates the overall signal quality low (57/100). With earnings roughly 50 days out, the next report is the most likely near-term test of the move.
MKSI price reaction
MKSI last traded at $239.27, down $28.04 (-10.49%) from the previous close of $267.31. The session traded on 0.8× average volume (below avg), so participation was unremarkable. Over the past month the stock has ranged between $239.27 and $320.74, and it currently sits about 0% of the way up that band.
Bullish and bearish analyst opinions on MKS Inc. (MKSI)
The consensus analyst price target on MKS Inc. (MKSI) is $408.14, 70.6% above the recent $239.27. Over the past 90 days analysts logged 0 upgrades, 13 maintains, and 0 downgrades. Here is how the bullish and bearish cases on MKSI line up.
▲ The bullish case
+Wall Street's consensus price target of $408.14 implies +70.6% upside from $239.27.
+The Street's most bullish target is $600.00 (+150.8%).
+MKS Inc. (MKSI) moved +6.53% from $324.28 to $345.44 on 2026-07-21.
▼ The bearish case
−Sharp 10.5% decline — elevated risk.
−MKS Inc. (MKSI) moved -4.12% from $304.92 to $292.35 on 2026-08-10.
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 14, 2026; other aggregators may differ. High and low targets show the range of estimates, not forecasts.
MKS Inc. fell 3.75% to $246.62, driven by a confluence of recent headwinds: CEO John Tseng-Chung Lee's sale of 10,000 shares (~$3 million) in late August, Mizuho's downward price-target revision from $360 to $330, and the stock's sustained underperformance relative to key moving averages (Yahoo Finance). Volume of 915k shares sits at 0.88x the historical average, indicating measured participation.
MKS Inc. fell 5.32% to $256.58, driven by valuation concerns cited by Yahoo Finance on 2026-08-28. Trading volume at 0.67x the expected intraday pace suggests below-average participation in the selloff.
Material / Earnings2026-08-27-0.3%
MKS Inc. (MKSI) moved -2.88% from $279.03 to $270.99 on 2026-08-27. We checked news, earnings announcements, analyst updates, SEC filings, and corporate actions — no company-specific catalyst was found. Volume was near its 5-day average, suggesting the move was not driven by unusual trading activity.
Material / Earnings2026-08-19-6.2%
MKS Inc. (MKSI) moved -7.42% from $304.16 to $281.60 on 2026-08-19, driven by profit-taking and cyclical weakness across the semiconductor equipment sector. Investors are re-evaluating high valuations and margin sustainability tied to AI infrastructure spending, with sector peers also declining in sympathy. Management's earlier warnings about near-term gross margin pressures and ramp costs have kept investors sensitive despite the company's earnings beat in August.
Material / Earnings2026-08-14+1.4%
MKS Inc. (MKSI) moved +2.89% from $302.01 to $310.73 on 2026-08-14. We checked news, earnings announcements, analyst updates, SEC filings, and corporate actions — no company-specific catalyst was found. The move occurred on below-average volume (0.8x the 5-day average).
Risk2026-08-10-4.1%
MKS Inc. (MKSI) moved -4.12% from $304.92 to $292.35 on 2026-08-10. We checked news, earnings, analyst updates, SEC filings, and corporate actions — no company-specific catalyst was found. The move occurred on light volume at 46% of the 5-day average.
MKS Inc. moved -6.01% intraday from $313.10 to $294.27. MKS Inc. stock is down about 2.5% on August 6, 2026, dropping to around $305–$313. The decline is driven by a broader technology and semiconductor sector pullback, tracking investor anxiety over high valuations and spending sustainability for AI infrastructure. Market Factors - Sector Sympathy: Tech and chip-related stocks faced renewed downward pressure, dragging down cyclical equipment providers like MKS. - Valuation Concerns: Investors are questioning whether massive AI hardware and wafer fab equipment spending has already been fully priced into valuations. Would you like details on MKS Inc.'s recent financial guidance or its upcoming earnings details?
Filings2026-08-06-7.0%
MKS Inc. (MKSI) filed a new 10-Q on August 6, 2026.
In-depth MKSI event analyses
Permanent, dated analyses of MKSI's most significant sessions.
MKSI tumbled 10.5% to $239.27. No single company-specific catalyst was confirmed during the move window, and it looks technical.
How much did MKSI stock fall?
MKSI lost 10.49% ($28.04) versus the prior close of $267.31, last trading at $239.27 on 0.8× average volume.
When is MKS Inc.'s next earnings date?
MKSI's next earnings report is estimated for 2026-11-04 — about 50 days away.
What is the analyst price target for MKSI?
The consensus analyst price target for MKSI is $408.14, about 70.6% above the current $239.27. Over the past 90 days, analysts recorded 0 upgrades, 13 maintains, and 0 downgrades.
How BestStocks tracks MKSI
This page is generated automatically by BestStocks' change-detection system after its price and volume cleared MKSI-specific materiality thresholds, triggering an evidence check. It draws on 20 tracked change events for MKSI, cross-checked against the data sources listed below. Price, volume, and market-capitalization figures are the live intraday quote as of September 15, 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.
