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RBBN, Ribbon Communications Inc.

Software asset-light Serial acquirer

We are a leading global provider of communications technology to service providers and enterprises.

The Ribbon name was created by the merger of Sonus Networks, Inc. and GENBAND US LLC ("GENBAND") in October 2017, with both companies specializing in secure high-performance Voice Over Internet Protocol ("VoIP") technology and solutions.

Prior to that, GENBAND acquired assets of Nortel's Carrier division in 2010, which included a world-class engineering and sales team, a broad deployment base of products and technology, and a recognized industry reputation and pedigree with customers around the world.

Latest annual: FY2025 10-K

RBBN · Ribbon Communications Inc.

The business

What it sells, where the money comes from, the kind of company it is.

Revenue · FY2025

$845M

+1.3% YoY · 0% 5-yr CAGR

Vital signs · TTM, with 5-yr average

Revenue $826M 5-yr avg $834M

Gross margin 49% 5-yr avg 51%

Operating margin −1.9% 5-yr avg −4.2%

ROIC −2% 5-yr avg −4%

Owner-earnings margin 2% 5-yr avg 1%

Free cash flow margin 2% 5-yr avg 1%

The business in brief

read the 10-K →

What this business is and what moves its needle, from its own SEC filings.

What it is: Revenue is Products (51%), Service Revenue, Maintenance (32%) and Service Revenue, Professional Services (17%).
Situation: Serial acquirer. Goodwill and acquired intangibles are 37% of assets, with meaningful acquisition spending in 4 of the record's 10 years; much of what this business is was bought, at prices the record carries.
What moves the needle: Operating margin has run around −5.9% through the cycle on a 53% gross margin, the operating line in the red even at its best — so the lever is whether the spending below the gross line can come down enough to clear a profit: revenue growth against the cost curve, and the cash runway until it does. Read this kind of business on retention and the cost of growth. On its own account, the filing leans hardest on customer concentration, set against the numbers in what the filing emphasizes, below.
Is it a good business?: Return on capital has rarely cleared the cost of capital (median −5%, above 15% in 0 of 10 years). Owner earnings, the cash-based check, have been thin too. This is price-taker territory, where the balance sheet and the cycle matter more than any multiple; the rest is in the 10-K.

Every line is arithmetic on the company's filings, shown in full in the sections below.

Where the money comes from

read the 10-K →

Revenue spreads across 3 lines, the largest Products at 51%.

Revenue by product line, FY2025

Products51%$435M
Service Revenue, Maintenance32%$271M
Service Revenue, Professional Services17%$139M

By geographyUnited States48%EMEA25%Asia Pacific21%Other6%

From the segment footnote of the company's own 10-K. Shares are of total revenue; the profit bar shows each segment's share of segment operating profit, before unallocated corporate costs.

The record

Ten years of arithmetic, read across the cycle.

The record, 2016–2025

realized figures from each filing · older years to the left

2016’16	2017’17	2018’18	2019’19	2020’20	2021’21	2022’22	2023’23	2024’24	2025’25	TTMTTMMar 2026
											Income statement
$253M	$330M	$578M	$563M	$844M	$845M	$820M	$826M	$834M	$845M	$826M	RevenueRevenue
66%	61%	60%	56%	53%	53%	49%	49%	53%	50%	49%	Gross marginGross mgn
14%	14%	11%	10%	8%	6%	6%	7%	8%	8%	8%	SG&A / revenueSG&A/rev
29%	31%	25%	25%	23%	23%	25%	23%	22%	21%	22%	R&D / revenueR&D/rev
($14M)	($55M)	($65M)	($189M)	$2M	($118M)	($48M)	($24M)	$17M	($3M)	($15M)	Operating incomeOp. inc.
−5.4%	−16.7%	−11.3%	−33.6%	0.2%	−13.9%	−5.9%	−2.9%	2.0%	−0.4%	−1.9%	Operating marginOp. mgn
($14M)	($35M)	($77M)	($130M)	$89M	($177M)	($98M)	($66M)	($54M)	$40M	$31M	Net incomeNet inc.
											Cash flow & returns
$19M	$8M	($10M)	$56M	$102M	$19M	($26M)	$17M	$50M	$51M	$33M	Operating cash flowOp. cash
—	—	$11M	$12M	$17M	$17M	$15M	$14M	$14M	$17M	$18M	DepreciationDeprec.
$13M	$18M	$45M	$161M	($18M)	$160M	$38M	$47M	$75M	($24M)	($37M)	Working capital & otherWC & other
$5M	$4M	$8M	$11M	$27M	$17M	$10M	$9M	$22M	$25M	$16M	CapexCapex
1.8%	1.2%	1.4%	1.9%	3.2%	2.0%	1.3%	1.1%	2.7%	3.0%	2.0%	Capex / revenueCapex/rev
$15M	$4M	($18M)	$45M	$84M	$2M	($37M)	$8M	$37M	$35M	$17M	Owner earningsOwner earn.
5.8%	1.2%	−3.0%	8.0%	10.0%	0.2%	−4.5%	0.9%	4.4%	4.1%	2.0%	Owner earnings marginOE mgn
$15M	$4M	($18M)	$45M	$75M	$2M	($37M)	$8M	$28M	$26M	$17M	Free cash flowFCF
5.8%	1.2%	−3.0%	8.0%	8.9%	0.2%	−4.5%	0.9%	3.3%	3.1%	2.0%	Free cash flow marginFCF mgn
$21M	$43M	$46M	$0	$347M	$0	$0	—	—	—	$0	AcquisitionsAcquis.
$10M	$0	$0	$5M	$0	$0	—	—	—	$9M	—	BuybacksBuybacks
-6%	-8%	-9%	-31%	0%	-12%	-5%	-3%	2%	-0%	-2%	ROICROIC
-6%	-6%	-13%	-27%	13%	-34%	-19%	-15%	-13%	9%	7%	Return on equityROE
−6%	−6%	−13%	−27%	13%	−34%	−19%	−15%	−13%	9%	7%	Retained to equityRetained/eq
											Balance sheet
$94M	$74M	$51M	$45M	$128M	$104M	$67M	$26M	$88M	$96M	$68M	Cash & investmentsCash+inv
$54M	$165M	$188M	$193M	$238M	$283M	$267M	$268M	$255M	$232M	$204M	ReceivablesReceiv.
$18M	$21M	$23M	$15M	$46M	$54M	$75M	$78M	$79M	$79M	$81M	InventoryInvent.
$7M	$46M	$45M	$31M	$63M	$97M	$96M	$85M	$88M	$80M	$77M	Accounts payablePayables
$66M	$141M	$165M	$176M	$220M	$240M	$247M	$261M	$246M	$231M	$208M	Operating working capitalOper. WC
$178M	$282M	$278M	$279M	$448M	$481M	$478M	$419M	$464M	$454M	$408M	Current assetsCur. assets
$77M	$243M	$290M	$207M	$328M	$344M	$330M	$341M	$329M	$315M	$299M	Current liabilitiesCur. liab.
2.3×	1.2×	1.0×	1.4×	1.4×	1.4×	1.4×	1.2×	1.4×	1.4×	1.4×	Current ratioCurr. ratio
$49M	$336M	$384M	$225M	$417M	$301M	$301M	$301M	$301M	$301M	$301M	GoodwillGoodwill
$308M	$911M	$957M	$815M	$1.5B	$1.3B	$1.3B	$1.1B	$1.2B	$1.2B	$1.2B	Total assetsAssets
—	$20M	$0	$48M	$385M	$370M	$326M	$233M	$337M	$333M	$332M	Total debtDebt
—	($54M)	($51M)	$4M	$256M	$266M	$259M	$206M	$249M	$237M	$264M	Net debt / (cash)Net debt
$219M	$615M	$590M	$483M	$687M	$527M	$518M	$453M	$405M	$449M	$419M	Shareholders’ equityEquity
7.8%	7.8%	1.9%	2.2%	1.6%	2.3%	2.3%	2.6%	1.9%	2.3%	2.6%	Stock comp / revenueSBC/rev
											Per share
49.4M	58.8M	104M	110M	145M	148M	157M	170M	174M	180M	176M	Shares out (diluted)Shares
$5.11	$5.61	$5.56	$5.13	$5.83	$5.73	$5.23	$4.85	$4.79	$4.70	$4.70	Revenue / shareRev/sh
$-0.28	$-0.60	$-0.74	$-1.19	$0.61	$-1.20	$-0.63	$-0.39	$-0.31	$0.22	$0.18	EPS (diluted)EPS
$0.29	$0.07	$-0.17	$0.41	$0.58	$0.01	$-0.23	$0.05	$0.21	$0.19	$0.09	Owner earnings / shareOE/sh
$0.29	$0.07	$-0.17	$0.41	$0.52	$0.01	$-0.23	$0.05	$0.16	$0.14	$0.09	Free cash flow / shareFCF/sh
$0.09	$0.07	$0.08	$0.10	$0.18	$0.12	$0.07	$0.06	$0.13	$0.14	$0.09	Cap. spending / shareCapex/sh
$4.44	$10.46	$5.68	$4.40	$4.75	$3.57	$3.31	$2.66	$2.32	$2.50	$2.39	Book value / shareBVPS

The diluted share count moved ×1.77 into 2018 — shares issued, not a split the totals corroborate — and the per-share figures carry the counts as filed.

Per-share growththe realized rate an owner's share compounded

	9-yr	5-yr
Revenue / share	−0.9%/yr	−4.2%/yr
Owner earnings / share	−4.6%/yr	−19.9%/yr
EPS	—	−18.5%/yr
Capital spending / share	+4.6%/yr	−5.3%/yr
Book value / share	−6.2%/yr	−12.1%/yr

The record, charted

FY2016–2025

Each measure over its full record; the current point and the worst year marked.

Share count

180Mpeak FY2025

ROIC

−0%low FY2019

Gross margin

50%low FY2022

Net debt ÷ owner earnings

6.8×peak FY2021

Owner earnings vs. net income

Owner earningsNet income

The accountant's number, and the cash an owner can take; the gap is the tell.

$35Mowner earningsvs.$40Mnet incomelow FY2022

Where the cash went

ReinvestBuybacksDividendsAcquisitionsRetainedBeyond op. cash

Each year's outlays against its operating cash: the mix, and how it drifts. The hatched cap is spending beyond that year's operating cash — financed from the balance sheet or borrowing, not operations.

FY2016FY2025

Owner-earnings bridge

FY2021–FY2025cash-flow statement, SEC EDGAR →

Net income is the accountant's number; owner earnings is the cash an owner could take out. The walk between them, off the cash-flow statement, and whether the gap is widening or holding.

In fiscal 2025 the business earned $35M of owner earnings, the operating cash left after the $17M it takes just to hold its position. It put $9M more into growth; free cash flow, after that spending, was $26M.

Reported net income$40M

Owner earnings$35M · 4% of revenue

	FY2025	FY2024	FY2023	FY2022	FY2021
Reported net income	$40M	($54M)	($66M)	($98M)	($177M)
Depreciation & amortizationnon-cash charge added back	+$17M	+$14M	+$14M	+$15M	+$17M
Stock-based compensationreal costnon-cash, but a real cost	+$19M	+$16M	+$22M	+$19M	+$19M
Working capital & othertiming of cash in and out, other non-cash items	−$24M	+$75M	+$47M	+$38M	+$160M
Cash from operations	$51M	$50M	$17M	($26M)	$19M
Maintenance capital expenditurethe spending needed just to hold position and volume	−$17M	−$14M	−$9M	−$10M	−$17M
Owner earnings	$35M	$37M	$8M	($37M)	$2M
Growth capital expenditurediscretionary; spent to get bigger, not to stand still	−$9M	−$9M	—	—	—
Free cash flow	$26M	$28M	$8M	($37M)	$2M
Owner-earnings marginowner earnings ÷ revenue	4%	4%	1%	-4%	0%

Owner earnings is the cash an owner could pull out without starving the business: operating cash less the maintenance capital it must spend to hold its position (here about $17M, roughly its depreciation, the rate its assets wear out). The other $9M of its capital spending is growth it chose, not upkeep it owed; charged only with the maintenance it must do, the business earns well more than the year's free cash flow shows. The cash-flow statement also adds stock comp back as non-cash, but it is a real cost paid in shares; counted as the expense it is (less $19M), owner earnings is nearer $15M.

Much of fiscal 2025's profit didn't arrive as operating cash; it sits in “working capital & other” above. That can be a real inventory or timing swing, or profit that doesn't run through operating cash at all: a heavy tax year, equity-method earnings, or investment income booked through investing. For a year like this, owner earnings understates the cash earned; the full cash-flow statement carries the rest.

Maintenance capex is estimated as depreciation where a growing business invests above it; free cash flow is the figure the scorecard's free-cash margin reads.

III

Quality & stewardship

Returns, the balance sheet, capital allocation, and pay.

Owner’s Scorecard

FY2025 10-K · source on SEC EDGAR →

Will it survive?

Can it pay its interest? —

Interest expense not tagged in the data

What this means
No usable interest-expense line was tagged in the filing data, but the balance sheet carries real net debt — so the interest burden here is unknown, not absent. Read the debt on the net-debt check below.
How heavy is the debt, net of cash? $237M

Net debt against an operating loss

Cash $96M − debt $333M

What this means
Netting $96M of cash and short-term investments against $333M of debt leaves $237M owed, with no operating profit this year to measure it against — understand that combination before anything else about the company. Net debt is the leverage figure that matters: the cash is already set against the debt. Strategic or illiquid investments aren't counted here.
How long is cash tied up? 99d

Long (60+ days)

DSO 100 + DIO 68 − DPO 69 days

What this means
Days cash is tied up between paying suppliers and collecting from customers. Lower is better; a long cycle means growth itself eats cash.

Is it a good business?

Return on invested capital -6%

Below average through the cycle

10-yr median, range -31%–2%; -0% latest = NOPAT ($3M) ÷ invested capital $686M

Industry peers: median -3%

What this means
The rate the business earns on the money tied up in it, Buffett's north star, because over time a stock tracks the ROIC beneath it. Above ~15% sustained hints at a moat; a return below the cost of capital (~8%) erodes value as a business grows rather than building it — the test Buffett weighs most. The headline is the median of the last 10 years (it ran -0% most recently), so one peak or trough year doesn't set the verdict. Asset-light businesses (R&D expensed, little capital) read artificially high, pair this with Owner Earnings.
Owner-earnings margin 4%

Thin, recently turned positive

latest $35M = operating cash $51M − maintenance capex $17M; positive each of the last 3 years, after an earlier loss stretch (10-yr median 1%)

Industry peers: median 10%

What this means
What an owner could take out without starving the business: operating cash less the maintenance capital it must spend to hold its position — Buffett's owner earnings. That's 4% of revenue this year, a 1% median across 10 years. It chose to put $9M more into growth, so free cash flow this year was $26M — the gap is investment, not weakness. Treating stock comp as the real expense it is (less $19M of SBC) leaves $15M.
Are earnings backed by cash? 1.30×

Cash-backed

Cash from ops $51M ÷ net income $40M

What this means
How much of reported profit showed up as operating cash. Above 1× is reassuring; well below suggests earnings lean on accruals. One year is noisy, growth and working-capital swings distort it, and this is operating cash, not free cash. Watch the multi-year trend.

How is the cash used?

Where do the earnings go? 26%

Reinvests most of it

Dividends + buybacks $9M ÷ Owner Earnings $35M

What this means
Of $35M Owner Earnings, $9M (26%) went back to shareholders, $0 dividends, $9M buybacks. But the buybacks barely exceed stock issued to employees ($19M SBC), net of dilution, little was truly returned. Returning most of it is the mark of a mature business with little left to reinvest at a high return; reinvesting most could mean a long runway, or empire-building. The split doesn't say which; the return earned on it (see ROIC) does.
Investing or harvesting? 1.51×

Expanding

Capex $25M ÷ depreciation $17M

What this means
Descriptive, not a grade. Above ~1× means investing faster than assets wear out (growth, or, sustained for years, today's earnings carrying less depreciation than tomorrow's will). Below means spending less than it's wearing out (efficiency, or a melting asset base). The ratio won't tell you which; the filings will.

Graham’s defensive tests · 0 of 5 met

Graham’s numerical criteria for the defensive investor (The Intelligent Investor, ch. 14), run on the filings. A floor of safety, not a buy signal; many fine modern businesses fail his strictest liquidity rules by design.

Adequate size Miss

Revenue ≥ $2B · $845M

What this means
Big enough to weather a storm. Graham's 1972 floor was ~$100M of sales (≈ $700M today); we use a $2B revenue line as a conservative modern stand-in.
Strong liquidity Miss

Current ratio ≥ 2× · 1.44×

What this means
Current assets at least twice current liabilities, near-term bills covered without touching the business. Strict by design: many cash-rich modern firms run leaner and miss it, holding their cushion in longer-dated securities.
Conservative debt Miss

Debt ≤ working capital · $333M vs $139M WC

What this means
Graham's rule that borrowings not exceed net current assets. Capital-heavy and buyback-heavy firms routinely fail it, read it next to interest coverage, not alone.
Earnings stability Miss

A profit every year (10-yr record) · 8 loss years

What this means
Graham wanted earnings in each of the past ten years, the stability a defensive owner leans on.
Dividend record Miss

Uninterrupted dividends · none paid

What this means
An unbroken dividend was Graham's mark of durability. He wanted twenty years; the filings show about ten, and a single suspension breaks the streak. Non-payers, many fine modern compounders, fall outside his defensive net by design.
Earnings growth —

Earnings +33% over the record · —

What this means
Earnings were negative early in the record, a growth rate isn't meaningful.
Moderate price —

P/E ≤ 15 and P/E × P/B ≤ 22.5 · decided by the price

What this means
Graham's valuation gate, the wall he kept between a sound business and a sound investment. Three-year average earnings are $-0.15/share (latest year $0.23), the averaged base the calculator's gate runs on, and book value is $2.55/share. Enter a price in “What the price implies” just below for the P/E, P/B, and whether it clears. But this is the rule Buffett outgrew: there's no hard P/E law, and a wonderful business can deserve a far richer multiple if the thesis holds, treat it as the bargain-hunter's floor, not a verdict on the price.

Durability & moat, 2016–2025

Whether the record’s returns held, and what the capital reinvested earned.

Profitable years 2 of 10

What this means
Lost money in 8 year(s), look at what happened there before trusting the average.
Return on capital ≥ 15% 0 of 9 yrs

What this means
A moat shows up as a high return on invested capital that holds year after year, not one good vintage.
Operating margin −11% → −0% (3-yr avg ends)

In the filing’s words The margin widened even though the filing names price competition — the gain came from volume or cost, not pricing power. Read where.

What this means
Through the cycle the operating margin widened — about −11% early to −0% lately, median −6% — pricing power intact or improving.
Reinvestment, incremental ROIC returns capital

What this means
The capital base barely grew: this business returns cash through dividends and buybacks rather than reinvesting. Judge it on the cash returned, not on compounding.
Owner earnings growth +16%/yr

What this means
Owner earnings grew about 16% a year over the record.
Worst year 2019 · −33.6% op. margin

What this means
Operations went underwater in 2019, understand why before trusting the good years.

Does AI threaten the moat?

Elevated contestability

The product is software or information, the very thing capable AI now produces more cheaply, so the moat is more contestable than the record alone implies.

In its own filing A competitive risk, new this year

Its FY2025 10-K names artificial intelligence as a competitive threat, in language that was not in the prior year's filing.

“In addition, if our competitors use AI tools to optimize operations and we fail to utilize AI tools in a comparable manner, we may be competitively disadvantaged.”

AI has collapsed the cost of building a capable substitute for the very thing this business sells. When a credible alternative can be assembled for a fraction of the incumbent's price, it is pricing power that erodes first, not revenue tomorrow. The live question is whether the moat survives that, not whether it held in the past. Whether that question is answerable at all is yours to decide, against your own circle of competence.

Read from the filing's own risk factors, paired with the industry's structure under its SIC code; the durability is read above, the price below.

All figures as filed; the source filing is linked above.

Current Position

as of the latest quarter, Mar 31, 2026

Can the business pay what it owes this year, off the freshest balance sheet: the quality of the assets, the debt actually coming due, and what a low ratio means here.

Current assets$408M

Cash & short-term investments$68M
Receivables$204M
Inventory$81M
Other current assets$55M

Current liabilities$299M

Debt due within a year$9M
Accounts payable$77M
Other current liabilities$213M

Current ratio1.37×all current assets ÷ what's due · Graham looked for 2×

Quick ratio1.09×stricter: inventory excluded

Cash ratio0.23×strictest: cash alone against what's due

Working capital$110Mthe cushion left after near-term bills

Debt due this year vs. cash$9M due · $68M cash covered by cash on hand, no refinancing forced · both figures from the Mar 31, 2026 balance sheet

Revenue, latest quarter vs. a year ago−10.3%the freshest read on whether the business is still growing

Current ratio, recent quarters1.5× → 1.4×

Deeper floors

Tangible book value($16M)equity stripped of goodwill & intangibles

Net current asset value($332M)Graham's net-net: current assets less all liabilities

Debt incl. operating leases$400M$69M of it operating leases

Deferred revenue$155Mcustomer cash collected before delivery; operating float

From the company's latest filing.

How the cash was used, 2016–2025

Over the record, the business generated $286M of operating cash; how management split it reads as a balanced allocator, splitting cash between the business, owners, and the balance sheet.

Reinvested$139M · 48%
Buybacks$23M · 8%
Retained (debt / cash)$125M · 44%

Returned to owners$23M
13% of the owner earnings the business produced over the span, $0 as dividends and $23M as buybacks.
Average price paid for buybacks$3.58
Across the years where the filing reports a share count, 3M shares were bought for $9M, about $3.58 each.
Net change in share count255.7%
The diluted count rose from 49M to 176M: issuance (stock pay, deals) outran any buybacks, so owners were diluted on net.
Dividend record—
No dividend line was reported in the filing data over the span; the record here neither confirms nor rules out a payout.

Buybacks are gross of stock issued to staff; the share-count line above is the net of that, the figure that decides whether owners gained. The average price paid blends a year of purchases (and any accelerated repurchase), so it is close, not exact. The record of where the cash went and on what terms.

Acquisitions & goodwill

from the balance sheet & the 10-year cash-flow record

Goodwill grows only when a company acquires and falls only when it concedes it overpaid. The size of that bet, the cash put into buying rather than building, and how much has already been written off.

Goodwill & intangibles$444M37% of all assets; the premium carried on the balance sheet for businesses acquired

Against book equity67%goodwill is this share of book equity; the rest is the company’s own retained and paid-in capital

Cash spent acquiring$457Mover 10 years buying other businesses, against $139M of capital spent building

$280M written down across 2 years (2019, 2021): goodwill the company has already conceded it overpaid for, charged against earnings. That is roughly 61% of the cash it put into acquisitions over the span. A write-down costs no cash (the cash went out when the deal was signed), but it is management marking its own past judgment to market.

Goodwill, acquired intangibles and equity from the latest balance sheet; acquisition spend and write-downs summed across the 10-year record, from the company's own filings.

Management, ownership & pay

read the proxy →

From the proxy: how much of the business the people running it own, and how they are paid, beside what the business earned for its owners in the same years.

Fiscal year	Chief executive	Pay, as filed	“Actually paid”	Owner earnings
2020	Bruce McClelland	$17.5M	$13.3M	$84M
2021	Bruce McClelland	$781k	$2.9M	$2M
2022	Bruce McClelland	$1.5M	−$6.5M	($37M)
2023	Bruce McClelland	$2.7M	$1.9M	$8M
2024	Bruce McClelland	$4.5M	$5.1M	$37M
2025	Bruce McClelland	$17.5M	$13.3M	$35M

Both pay figures are the company’s own, from the pay-versus-performance table its proxy statement files. “As filed” is the Summary Compensation Table total: salary, bonus, and equity awards at their value on the day of grant. “Actually paid” is the SEC’s prescribed recalculation, which re-marks those equity awards to what they became as they vested; it can swing far above or below the filed figure in either direction, and negative years occur. Owner earnings are the whole business's, from the record above, for the same fiscal years.

Insider ownership4%
The stake all directors and executive officers hold together, per the 2026 proxy: skin in the game, the first thing Munger reads.
CEO pay ratio223:1
What the chief earns for every dollar the median employee makes, per the 2026 proxy. A high ratio alone settles nothing; some businesses are genuinely top-heavy in scarce skill. A runaway figure is where Buffett starts asking whether the board is doing its job.
Stock-based compensation$19M
The slice of the business handed to employees in shares this year, 2% of revenue. Buffett's oldest accounting fight: this is compensation, compensation is an expense, real whether or not the headline earnings admit it. One trap: the cash-flow statement adds SBC back, so the operating cash, and the owner earnings drawn from it, are flattered by exactly this amount; counted as the cost it is, what an owner keeps is lower.

Inverting the record

Invert: instead of why Ribbon Communications Inc. is a good business, the question is what would make owning it a mistake, and whether those marks are in the record. Disconfirming tests across 2016–2025.

1 of the 4 tests turned up something to look into; the other 3 came back clean.

Look hereDid the share count rise anyway?255.7%
Diluted shares grew 255.7% over 2016–2025, even as the company spent $23M on buybacks. The repurchases were outrun by issuance — to staff, in a raise, or in a deal — and the filing says which; owners' slice still shrank. Read the buyback line beside this one, not on its own.

And these came back clean

Is it less profitable than it was?
Did receivables and inventory outpace sales?
Are "one-time" charges a yearly habit?

Each test is read from the filings and is noisy alone; a flag can mark a cyclical trough or a year of heavy investment as easily as a problem. The filing says which.

What an owner would ask, FY2025

read the 10-K →

How much of the revenue rides on one buyer?
≈$339M · 41% of revenue on the largest customers (TTM)
“Our top five customers represented approximately 41% of our revenue in the year ended December 31, 2025.”verify →

The questions the record and the charts do not answer on their own; each carries the figure and the place to look.

Peers, Software

The same industry, side by side on owner economics. Each figure is a through-cycle median, so a peak or trough year can’t distort it; the group median at the foot is the line to read each against.

Company	Revenue	Gross margin	Op. margin	ROIC	Owner earn. margin
IOTSamsara Inc.	$1.6B	73%	-37.1%	-28%	-10%
WAYWaystar Holding Corp.	$1.1B	—	15.5%	3%	14%
RPDRapid7	$860M	70%	-17.1%	-18%	6%
NTCTNetScout Systems Inc.	$859M	74%	3.2%	1%	22%
CXMSprinklr Inc.	$857M	70%	-6.6%	-3%	5%
RBBNRibbon Communications Inc.	$845M	53%	-5.6%	-5%	3%
FRSHFreshworks Inc.	$839M	81%	-22.5%	-23%	11%
NRDSNerdWallet Inc.	$837M	92%	0.8%	1%	10%
Group median	—	73%	-6.1%	-4%	8%

The price

What a price has to assume.

What the price implies

reverse-DCF

Type today's close and see the owner-earnings growth you'd have to believe to justify it, beside what Ribbon Communications Inc. has delivered.

Ribbon Communications Inc.’s latest year runs above its own through-cycle margin — the reported figure may flatter a peak. So the tool opens on the through-cycle base, Graham’s averaging cutting both ways; clear the toggle below to read the latest year exactly as reported.

Today’s price $

Through the cycle, Ribbon Communications Inc. earns about $23M on its 2.7% median owner-earnings margin. This year’s 4.1% margin runs above that; the reported figure may flatter a peak you'd be paying on. Normalize, below, values the price on that through-cycle figure rather than the latest year. It comes pre-checked here for that reason, the same rule that already normalizes a trough; clear it to price the year as filed.

Base Normalize · through-cycle ($23M) Net of stock comp (−$21M)

—

The assumptions Required return 9% Years of high growth 10 Terminal growth 2.5%

9.0% = the 4.55% 10-year Treasury (Jul 15, 2026) + 4.45 points of equity premium. The rate you require is yours to set.

Enter a price above to run it.

Implied by the price—

Owner-earnings growth · ’16→’25+13%/yr

Owner-earnings yield—

P/E (3-yr earnings ’23–’25)—

P/B—

Graham’s price gate—

Graham capped the multiple at 15×; Buffett and Munger let that rule go: a wonderful business can deserve 50× if the thesis holds. The gate marks the bargain-hunter's floor.

Against a high-grade bond: Graham’s yardstick bond yield%

Prefilled with the 10-year Treasury (4.55%, as of Jul 15, 2026). Edit it for today’s exact figure, or a AAA corporate yield.

Graham measured a stock against the bond you could own instead, the heart of his margin of safety. Enter a price above to weigh the owner-earnings yield against this bond.

Owner earnings $17M on 176M shares outstanding, per the 10-Q cover, as of 2026-04-27; net debt $264M. The base opens on the through-cycle figure (the latest year sits above the record’s own median, and Graham’s averaging cuts both ways); clear Normalize to use the year as filed. Net of stock comp treats option pay as the expense it is. The dials set the multiple a growth belief justifies; the price, and every dollar on this page, is yours.

Weigh RBBN against another business →

Cite: Owner Scorecard, "Ribbon Communications Inc. (RBBN), the owner's record," https://ownerscorecard.com/c/RBBN, data as of 2026-07-09.

Manual order: ← RBB its page in the Manual RBC →

Industry order: ← QXL the Software chapter RBLX →