IESC vs JAZZ: Which Is the Better Buy in 2026?

Same yardstick, side by side (as of October 2026). Valuation lined up like this is most meaningful for two names in the same corner of the market, which these are. Figures are approximate; verify before investing.

The metrics above tell you which is the marginally better business. The bigger risk for most people is not picking the slightly worse stock, it is over-concentrating. IESC and JAZZ share themes, so owning both, or adding either to what you already hold, can quietly push a large share of your portfolio into one bet.

This is the part a generic comparison page cannot answer, because it depends on what you own. Connect your brokerage and Walnut shows your real, combined IESC and JAZZ exposure, flags overlap with your existing positions, and tells you if adding one would tip you past a concentration you are comfortable with, read-only by default, with your login staying at your broker. Walnut is not an investment adviser.

IES Holdings designs, installs, and maintains integrated electrical and technology systems across the United States, operating through four segments: Communications (network and electrical infrastructure for data centers and mission-critical facilities), Infrastructure Solutions (custom engineered products such as switchgear and power distribution), Residential (electrical work for single and multi-family housing), and Commercial & Industrial. In fiscal 2025 (year ended September 30, 2025), the company generated roughly $3.37 billion in revenue, with the Communications segment at about $1.14 billion (up 47%) and Infrastructure Solutions at about $498.7 million (up 42%), both driven by data center demand, while the Residential segment (about $1.30 billion) declined 6% on softer housing activity.

Full IESC guide

Jazz Pharmaceuticals is an Ireland-domiciled specialty biopharmaceutical company that develops and markets treatments in neuroscience and oncology. Its largest products are Xywav and Xyrem (low-sodium and legacy oxybates for narcolepsy and idiopathic hypersomnia) and Epidiolex/Epidyolex (a cannabidiol treatment for rare epilepsies), which together anchor a neuroscience portfolio generating several billion dollars a year. Jazz has expanded aggressively into oncology through Zepzelca (small cell lung cancer), Rylaze (pediatric leukemia), Ziihera/zanidatamab (a HER2-directed bispecific antibody) and Modeyso (dordaviprone for diffuse glioma, added via the 2025 Chimerix acquisition).

Full JAZZ guide

Both fit overlapping themes, but they are not interchangeable. The useful comparison is which set of drivers and risks you want exposure to.

• IESC drivers: Data center and AI infrastructure demand; Backlog and margin expansion.
• JAZZ drivers: Sleep franchise durability; Oncology pivot and Ziihera.

A faster-growing, richer-valued name usually swings harder, so it suits a longer horizon and a higher tolerance for volatility; a steadier, more cash-generative business suits a more conservative or income-minded investor. The honest test is which set of risks you could hold through a drawdown: IES is a project-based contractor whose results depend on construction activity, labor availability, and project execution, all of which are cyclical. For JAZZ, jazz is concentrated in a few large products, so any acceleration of generic or branded competition against Xywav or Epidiolex could pressure revenue and the stock.

Growth-minded investors who believe the theme has years to run tend to accept the richer multiple for more upside; value-minded investors lean toward the cheaper forward earnings and steadier profile. Pick IESC if you believe its drivers more; JAZZ if you believe its. Many investors hold both, but since they share themes, that is a concentrated bet, not diversification. Decide deliberately and check overlap. For the full detail, see the IESC and JAZZ guides.

IESC. IES has turned a strong fiscal 2025 into a faster fiscal 2026, with June quarter revenue up ~40% and trailing earnings up to ~$454 million, so the trailing P/E has fallen to ~23 even though the stock is up ~27% this year. On the ~$13.51 of EPS analysts expect for fiscal 2027, the shares trade near ~19x. The stock sits ~37% below its 52 week high of ~$408 after a ~20% fall in the month to October 16, 2026, and the balance sheet carries more cash than debt.

JAZZ. Jazz combines several billion dollars of high-margin drug revenue, with gross margins above ~90%, with strong non-GAAP earnings, yet trades near ~8 times forward earnings and ~8 times EV to EBITDA. The gap reflects investor concern about patent cliffs and competition rather than current profitability, and the June-quarter earnings miss pulled the shares well off their highs. Net debt of roughly ~$2.2 billion is comfortably covered by free cash flow, so capital allocation and acquisition discipline matter more than solvency. The 22 analysts tracked by Yahoo Finance carry a mean target near ~$295.

Headline figures (approximate, October 2026): IESC shows revenue (ttm, jun 2026) ~$4.0 billion; fiscal Q3 2026 revenue ~$1.24B, up ~40%, net income (ttm) ~$454 million; fiscal Q3 2026 ~$154M, eps ~$11.25 trailing; fiscal Q3 2026 ~$3.79 vs ~$2.41 expected, margins (ttm) Gross ~26%, operating ~14%, net ~11%; JAZZ shows revenue (ttm) ~$4.6B, 2026 revenue guidance ~$4.60B to $4.75B (raised in August), q2 2026 revenue ~$1.21B (up ~15.5% YoY); adjusted EPS ~$5.71 vs ~$6.18 expected, net income (ttm) ~$941M, a ~20% net margin.

IESC and JAZZ are related but distinct: same themes, different businesses and risks. Neither wins in the abstract; the right pick is whichever thesis you actually believe, sized so you are not over-concentrated in one theme. Walnut can show your combined IESC and JAZZ exposure against your real portfolio. It is not an investment adviser.