The story

Every year, thousands of investors read Buffett's annual letter and think they've read the Berkshire filing. They haven't. The letter is a curated highlight reel. The 10-K is where the actual business lives — and 2025's edition contains several things that deserve considerably more attention than they received.

Start with the float. Berkshire's insurance subsidiaries held $176B in float at year-end — the money collected from policyholders before claims are paid. This isn't debt. It's essentially a free loan from customers that Berkshire invests for its own account. That float grew $5B in 2025 and is now parked largely in $321B of U.S. Treasury bills, earning yields that didn't exist three years ago. The insurance investment income line — $9.4B — is the quiet engine of the whole enterprise, and it grew even as overall operating earnings declined.

The headline miss was a drop in overall operating earnings from $47.4B to $44.5B, driven primarily by lower insurance underwriting profit as catastrophe claims normalized. But the subsidiary businesses told a genuinely different story. BNSF earned $5.5B, up 9%, and management described the railroad as moving freight faster than in nearly any year in the company's history. Berkshire Hathaway Energy grew 7%. Manufacturing, services and retail — the unglamorous collection of See's Candies, Pilot Flying J and dozens of others — earned $13.6B, up 4%.

Segment earnings

Manufacturing, service & retail
$13.6B  +4%
Insurance investment income
$9.4B  –2%
Insurance underwriting
$5.7B  +1%
BNSF railroad
$5.5B  +9%
Berkshire Hathaway Energy
$4.0B  +7%
The number Buffett wants you to focus on

$46 billion in operating cash flow — above the five-year average of $40B. While GAAP net earnings gyrate with investment mark-to-market swings, this number measures the actual cash the business generates. Berkshire threw off more cash in 2025 than most S&P 500 companies are worth in their entirety.

The story nobody covered: the Japan trade is still active. In April 2025, Berkshire issued ¥90 billion of senior notes at just 1.6% — borrowing in yen to fund positions in Japanese trading houses yielding considerably more. The annual report mentions this in a single paragraph on page 94. It deserves considerably more attention, because it represents one of the most elegant carry trades in modern investing — and it's still being added to.

Bull vs. bear

Bulls see

  • $176B float growing — essentially free capital earning 5%+ in T-bills
  • BNSF's best operational year in history — pricing power intact
  • $321B T-bill pile is dry powder for the next market dislocation
  • Japan yen trade still active — borrowing at 1.6% to fund higher-yielding positions
  • 387,800 employees across recession-resistant businesses

Bears see

  • Operating earnings down 6% — underwriting profit normalizing after pandemic-era tailwinds
  • Succession still unresolved beyond Greg Abel as CEO designate
  • $321B in T-bills = no bold capital allocation despite record cash mountain
  • BHE wildfire liability exposure still a risk after 2023 Maui losses
  • At this size, what acquisition actually moves the needle?

Flags worth monitoring

  • T-bill pile at $321B, up from $286B: Berkshire is still waiting. The pile grew in 2025. What is it waiting for? This is the most important unanswered question in the filing — and management doesn't answer it.
  • Japan yen notes at 1.6%: The ¥90B April 2025 issuance is the latest addition to a multi-year trade that's been quietly compounding. Total yen-denominated debt is now significant. The trading house positions have been held for years with no announced exit thesis.
  • BHE issued $3.1B of new term debt at 6.4% average rate: Energy capex is accelerating, partly driven by grid infrastructure demand. This is potentially a major growth driver — but also a reminder that BHE's wildfire liability tail risk hasn't been fully resolved.
  • Annual meeting May 2, 2026: First full year with Greg Abel as operational lead. Watch for any shifts in capital allocation language — Buffett set an extraordinarily high bar for acquisitions. Does Abel maintain it or lower it?

Follow-up questions for deeper reporting

$321B in T-bills is the largest corporate cash hoard in history — what would trigger Berkshire to deploy it, and has Abel signaled any different threshold than Buffett's historically patient standard?
The Japan yen note issuance at 1.6% suggests the trade is still being added to — how large has the total position in Japanese trading houses become, and what's the exit thesis?
BNSF had its best operational year by throughput metrics yet earned $5.5B — what's the ceiling on railroad earnings given regulated pricing, and how does precision scheduled railroading change that math over the next decade?

The filing

All analysis is based on Berkshire Hathaway's 10-K for fiscal year ended December 31, 2025, filed March 2, 2026. All figures from the annual report and accompanying press release.

View original filing on SEC.gov ↗