ASPN, Aspen Aerogels Inc.

Will it survive?

• Can it pay its interest? —
  No meaningful interest burden
  Little or no interest expense reported
  What this means

  Little or no interest expense reported, the business isn't leaning on lenders to operate.

• How heavy is the debt, net of cash? +$42M
  Net cash
  Cash $157M − debt $115M
  What this means

  Cash and short-term investments exceed every dollar of debt by $42M, on net the company owes nothing, and can act from strength when others can't. 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? 88d
  Long (60+ days)
  DSO 47 + DIO 62 − DPO 21 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 -22%
  Below average through the cycle
  10-yr median, range -177%–10%; -154% latest = NOPAT ($299M) ÷ invested capital $194M
  Industry peers: median 12%
  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 -154% 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 -11%
  Consumes cash through the cycle
  10-yr median margin, range -57%–5%; latest ($5M) = operating cash $33M − maintenance capex $37M
  Industry peers: median 13%
  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 -2% of revenue this year, a -11% median across 10 years. Treating stock comp as the real expense it is (less $9M of SBC) leaves ($13M).

• Are earnings backed by cash? $33M
  Loss, but cash-generative
  Net income ($390M) · cash from operations $33M
  What this means

  The company reported a net loss, so a conversion ratio isn't meaningful. What matters then is whether operations still threw off cash, here, they did.

How is the cash used?

• Where do the earnings go? —
  Not enough data
  What this means

  The filing data didn't include the inputs for this check.

• Investing or harvesting? 0.83×
  Maintaining
  Capex $37M ÷ property depreciation $45M
  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.

The promise and the pay packet

• What does winning a customer cost? 10%
  Sells itself
  Selling and marketing $28M ÷ revenue $271M
  What this means

  Sales and marketing as a share of revenue, kept apart from administrative overhead because it answers a different question: how much a business must spend to win the next customer. A company whose product pulls customers in spends little here and keeps the difference; one that must buy its growth is running to stand still, and the spending has to keep rising for revenue to keep rising. Read it beside the growth rate, not alone.

• Is the buyback buying ownership, or mopping up? 3.2%
  Stock pay, share count unread
  Stock compensation $9M (fiscal 2025), 3.2% of revenue · no repurchases · the share count is not comparable across these years (a split or a first listing sits in the record), so the drift is withheld
  What this means

  Stock handed to employees is a real cost paid in the owner's own currency: it is charged against profit, but the shares it creates are permanent. Many companies repurchase stock at the same time, which looks like a return of capital and often is not — if the count barely moves, the cash merely cancelled the pay packet and bought the owner nothing. The three states worth telling apart are a count genuinely shrinking, a count standing still despite large repurchases, and a count rising because the issuance was never offset at all.

Graham’s defensive tests · 2 of 4 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 · $271M
  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 Pass
  Current ratio ≥ 2× · 3.90×
  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 Pass
  Debt ≤ working capital · $115M vs $180M 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) · 9 loss years
  What this means

  Graham wanted earnings in each of the past ten years, the stability a defensive owner leans on.

• Dividend record —
  Uninterrupted dividends · no dividend line tagged in the data
  What this means

  An unbroken dividend was Graham's mark of durability. This record carries no dividends-paid line in any year — common for partnerships, whose distributions file under tags the chain doesn't read — so the criterion is withheld rather than judged on silence.

• 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 $-1.69/share (latest year $-4.69), the averaged base the calculator's gate runs on, and book value is $2.84/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 1 of 10
  What this means

  Lost money in 9 year(s), look at what happened there before trusting the average.

• Return on capital ≥ 15% 0 of 5 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 −20% → −49% (3-yr avg ends)

  In the filing’s words The filing attributes gains to higher prices, but the margin in the record has not followed — the claim outruns the result here.

  What this means

  Through the cycle the operating margin slipped — about −20% early to −49% lately, median −22% — competition or costs are biting in.

• Reinvestment, incremental ROIC —
  What this means

  The reinvested base moved too little against the change in profit to read a reliable return on it here — the figure would be a small-denominator artifact, not a moat. Judge this one on the owner-earnings record and the cash it returns instead.

• Worst year 2025 · −139.5% op. margin
  What this means

  Operations went underwater in 2025, understand why before trusting the good years.