Why Is Harmonic (HLIT) Stock Up 26% Premarket? Two Customers Are 63% of It

TL;DR

• Harmonic's fiscal Q2 2026 broadband revenue was $133.5 million, up 54% from $86.9 million a year earlier, and above the company's own $115-125 million guide.
• Full-year broadband revenue guidance went up to $505-525 million from $475-495 million. That is the second raise of 2026; the range opened the year at $440-480 million.
• Non-GAAP operating income was $31.3 million against a $23-28 million guide, on a 53.0% non-GAAP gross margin. GAAP operating income was $23.6 million.
• HLIT quoted $15.14 in Thursday premarket, up 26.17% on Wednesday's $12.00 close. That is a premarket snapshot taken at 5:48am ET, not a close.
• Two customers were 63% of broadband revenue, up from 58% in Q1. All of the sequential growth came from that pair, and the rest of the customer base got slightly smaller.

Why Is Harmonic Stock Up?

Harmonic beat its own broadband revenue guidance by about $13 million at the midpoint, raised the full-year range for the second time this year, and posted a record backlog, all in its first full quarter as a broadband-only company. Reported Wednesday after the close, the stock was quoted at $15.14 premarket Thursday, up 26.17% from Wednesday's $12.00 close.

The Board

Every operating line cleared its guide. The concentration line went the other way.

The Quarter Against Its Own Guide

Harmonic guided fiscal Q2 broadband revenue to $115-125 million and delivered $133.5 million. It guided non-GAAP operating profit to $23-28 million and delivered $31.3 million. Gross margin came in at 53.0% on a non-GAAP basis and 52.4% on GAAP, both comfortably inside the range the company had set.

Growth accelerated: 54% year over year, against the 20% the broadband line was running last year. Backlog and deferred revenue hit a record $587.6 million, up 71%, which is the number that made the guidance raise credible rather than hopeful.

The reported EPS lines are messier than the operating lines, which is why the headlines disagreed with each other overnight. Continuing operations produced $0.16 of GAAP EPS and $0.21 non-GAAP. Including discontinued video operations, the company printed a small GAAP net loss of $2.3 million, or $(0.02) a share, and several outlets ran a $0.24 non-GAAP figure covering the whole company. Three different EPS numbers, all defensible, all describing the same quarter.

Where the Growth Actually Came From

Two customers, historically Comcast and Charter per Light Reading's reporting on the segment splits, were 63% of broadband revenue this quarter. In Q1 they were 58%, or $71.1 million of $121.7 million.

Run the arithmetic across the two quarters and the picture sharpens. The top two went from roughly $71 million to roughly $84 million. Rest-of-market went from $50.6 million to just under $50 million, so it slipped a touch sequentially even while it grew 44% against last year. Total broadband revenue rose about $12 million quarter on quarter, and more than all of that came from the two anchor accounts.

Management framed rest-of-market as "way past the lab trials" on the call, which I believe as a description of the pipeline. It is not yet visible in the sequential numbers. Q1's rest-of-market growth was 78% year over year; this quarter it was 44%. The diversification story is real on a twelve-month view and it went backwards on a three-month one.

That matters because concentration is the whole bear case here. A vendor whose two biggest customers are cable operators is a vendor whose revenue tracks two capital budgets. Comcast and Charter are both mid-cycle on DOCSIS 4.0 upgrades. When those budgets are set for the year, Harmonic's year is largely set with them.

The Pure-Play Repricing

Harmonic closed the $145 million sale of its video business to MediaKind on June 16, leaving one reportable segment. That is what the market is now pricing: a single-product broadband company growing 54% with a record backlog, rather than a conglomerate carrying a shrinking video appliance business.

The balance sheet moved with it. Cash was $231.9 million at July 3, against $124.1 million at December 31. The company bought back $42.95 million of stock in the first half.

At the premarket $15.14, the market cap is roughly $1.6 billion on 108.5 million shares. Full-year non-GAAP EPS is guided to $0.67-0.75, so the stock is trading near 21 times the midpoint of a number management raised this week. The 52-week range is $8.47 to $17.68, meaning even after a 26% gap the stock has not reclaimed its own high.

What the Guide Implies for the Back Half

This is where I would slow down. The raise is genuine: after Q2's beat, the old $475-495 million range implied about $230 million for the second half, and the new $505-525 million implies about $260 million. Thirty million dollars of added expectation is not a rounding adjustment.

It also implies a flat run rate. Q3 broadband revenue is guided to $125-135 million, and subtracting Q1's $121.7 million, Q2's $133.5 million and that Q3 range from the full-year guide leaves roughly $125-135 million for Q4 as well. So a company that just delivered $133.5 million has guided to roughly $130 million a quarter for the rest of the year.

I read that as conservatism rather than a warning, given the backlog. But anyone buying a 26% gap on an acceleration narrative should know the company's own guide does not contain further acceleration. If Q3 comes in at the top of the range and the full-year number goes up a third time, the thesis is intact. If Q3 lands mid-range, the run rate story is what it is.

For where this sits in the wider AI-and-bandwidth complex, Lumentum's fiscal Q4 is the useful comparison: optical components growing 109% with a GAAP loss line that has nothing to do with the business. Coherent reports into the same demand picture. Harmonic is a different animal from both, closer to a cable capex proxy than an AI supplier, and the multiple should reflect that.

The One-Line Read

Harmonic's first quarter as a pure-play broadband vendor cleared every operating line and raised the year, and two customers paid for all of it. I would want a third leg before paying up.

Full calendar for the session, including PPI at 8:30am and Applied Materials tonight, is in the August 13 hour-by-hour, and dates for the rest of the season sit in the earnings calendar.