MTSI · MACOM Technology Solutions Holdings, Inc. · Stock research

Current Thesis

The earnings gap has been given back. On 2026-08-06 MACOM guided fiscal Q4 to $415–425M against $368.7M consensus with adjusted EPS of $1.97–2.03 versus $1.57, and price moved from a $263.46 close (2026-08-05) to $301.64, then on to $316.44 by 2026-08-14. Five sessions later the stock closed $266.61 (2026-08-21) — within about 1% of where it traded the day before the guide, without a single piece of company news in between. The 2026-08-19 session alone was -7.8% to $269.98.

The narrative leg on offer is unchanged and still measurable: MACOM's analog and photonics content per optical port — TIAs, laser and modulator drivers, 200G PAM4, LPO chipsets — compounding as datacenter links step from 800G to 1.6T, with an order book running ahead of shipments (1.6:1 book-to-bill, Q3 call 2026-08-06). What changed is the market's willingness to pay up for it.

The narrative is maturing, dated to the 2026-08-14→2026-08-21 round trip. The fundamentals accelerated and the bid did not follow. That is a different regime from the one described on 2026-08-06, when a new guide 13% above the Street bought a durable re-rating.

Bullish and bearish views on MACOM Technology Solutions Holdings, Inc.

The model's bull view on MACOM Technology Solutions Holdings, Inc. (MTSI), in brief: Q4 FY26 guide (2026-08-06): $415–425M revenue vs $368.7M consensus, adjusted gross margin 60–61%, adjusted EPS $1.97–2.03 vs $1.57. The bear view: The round trip is the new datapoint. $263.46 (08-05) → $316.44 (08-14) → $266.61 (08-21). A guide 13% above consensus produced no lasting price. Sellers met the news. This ownership base sells the group, not the company. July took price from the $409.68 area to a $248.71 close… Both cases follow in full.

Bull Case

• Q4 FY26 guide (2026-08-06): $415–425M revenue vs $368.7M consensus, adjusted gross margin 60–61%, adjusted EPS $1.97–2.03 vs $1.57. Guidance, not the beat, drove the initial move.
• Data Center $137.6M in FQ3, roughly +40% sequentially (Q3 call, 2026-08-06): attributed to 800G/1.6T platforms and 200G PAM4.
• Record 1.6:1 book-to-bill (Q3 call, 2026-08-06): third straight quarter of rising bookings coverage (1.3 → 1.5 → 1.6), Data Center the standout across all three end markets.
• Management's own forward frame (2026-08-06): annualizing the Q4 guide midpoint implies 27–28% company growth and roughly 50% Data Center growth.
• Coverage restocking after the July de-rating: Needham Buy $410 (2026-08-06), Evercore ISI Outperform $475 (2026-08-07), Benchmark reinstated Buy at $375 (2026-08-17, shares +3% that session), BMO Capital initiated Market Perform at $335 (2026-08-21). Every published target sits above the 2026-08-21 close of $266.61.
• Valuation reset without an estimate reset: stockanalysis.com shows a forward P/E of 32.34 and a $20.36B market cap on 2026-08-21, after a 34.9% drawdown from the $409.68 52-week high on the adjusted closing series.

Bear Case

• The round trip is the new datapoint. $263.46 (08-05) → $316.44 (08-14) → $266.61 (08-21). A guide 13% above consensus produced no lasting price. Sellers met the news.
• This ownership base sells the group, not the company. July took price from the $409.68 area to a $248.71 close (2026-07-30) with no guidance cut, after Russell 1000 Value and Russell Midcap Value removal in the 2026 reconstitution. The 2026-08-19 drop repeated the pattern inside an optics-complex profit-taking episode.
• BMO's initiation is a neutral rating from a fresh set of eyes (2026-08-21). New coverage arriving at Market Perform after a 12-month advance of roughly 115% is a different signal from a target raise by an incumbent bull.
• The Q4 bar is large. $415–425M is a steep sequential step from $342.2M. The November print must clear it and guide FQ1 FY27 consistently with the ~50% Data Center base case.
• Book-to-bill above 1.5 can reflect lead-time hedging. Normalization toward 1.0 removes the strongest single number in the story.
• No company-specific catalyst inside 30 days. Between now and early November the name trades on AI-capex sentiment and peer prints.

Setup & Price Structure

Reference close $266.61 on 2026-08-21 (+0.16% that session), RSI(14) 52.8, -34.9% from the $409.68 52-week high, and a three-month price change of -30.9%.

The base has four marked closes: $248.71 (2026-07-30, capitulation low), $263.46 (2026-08-05, the last pre-print close), $301.64 (2026-08-06, the post-guide gap close) and $316.44 (2026-08-14, the failed high). Price now sits between the first two, meaning the entire post-guide advance has been retraced and the 08-06 gap is closed. RSI at 52.8 is neutral — neither the washed-out condition of late July nor the extension of mid-August.

Positioning observables, stated as observables: four sell-side actions in the 15 sessions after the print, with consensus target $395.33 (stockanalysis.com, 2026-08-21) sitting 48% above spot — the entire published target set is above the market; the Russell value indexes no longer hold the name after the 2026 reconstitution, removing one natural bid; the recent filings record shows no company filings after the 2026-08-06 8-K, so there is no insider-transaction evidence either way in this window; and the dominant near-term input is another company's print three sessions out.

Catalyst Calendar (next 30 days)

• 2026-08-26 — NVIDIA Q2 FY27 results (quarter ended 2026-07-26), call 5:00pm ET. The sector read-across for 800G/1.6T optical port demand.
• ~2026-09-08 to 2026-09-10 (est.) — European Conference on Optical Communication (ECOC) week; historically a venue for 1.6T and LPO product announcements across the optical component group.
• ~2026-10-02 (est.) — fiscal Q4 FY26 quarter end, the period guided to $415–425M and 60–61% adjusted gross margin.
• ~2026-11-05 (est.) — Q4 and FY26 results plus FQ1 FY27 guidance.

What Would Change Our Mind

The structure that matters now is the July shelf, not the August high. The post-guide advance is already gone; what has not gone is the 2026-07-30 capitulation close of $248.71. A weekly close below $248 takes that out and converts a sharp pullback into a trend failure, and it would do so with the strongest bookings quarter in the company's history on the tape — which is the point at which the fundamental leg stops explaining the price.

Three non-price conditions would do the same work. First, NVIDIA's 2026-08-26 data-center number and 2027 commentary landing below consensus, which is how the July de-rating started. Second, the November print coming in below the $415M low end of the guide, or FQ1 FY27 guidance implying Data Center growth materially under the ~50% base case stated on 2026-08-06. Third, book-to-bill falling back toward 1.0.

The reverse case is equally specific: reclaiming the $301.64 post-print gap close on a weekly close would say the round trip was group-driven de-risking rather than a verdict on the guide.

Correlation Notes

MTSI trades with the AI optical-interconnect complex — COHR, LITE, CRDO, ALAB, AAOI — and the 2026-08-19 session was an optics-specific drawdown rather than a broad semiconductor unwind. The July 2026 episode moved this name 40% peak-to-trough on hyperscaler-capex-digestion fear with no company guidance change, so the correlation is to AI-capex sentiment first and to MACOM's own bookings second. Secondary exposures: telecom/SATCOM oversupply headlines, and compound-semiconductor wafer supply through the May 2026 IQE long-term agreement, which carries a £45M equity/convertible commitment for GaAs and InP wafers.