How these work: Each workbook is a single self-contained page. Public-holding prices and bond quotes update automatically every few minutes; everything else (multiples, cost bases, debt mark factor, share counts, tax rates) is editable. Nothing is saved server-side — your inputs live in your browser only. Not investment advice.
Available now
NASDAQ: RILY
BRC Group Holdings (B. Riley)
Diversified financial services. Holding company with 31% of Babcock & Wilcox plus 7 operating segments and ~$1.3B of senior debt. Trades at deep discount to liquidation value; debt market discounts solvency concerns. Includes corporate cap-gains tax modeling and a face↔market debt slider.
NYSE: BRK.A / BRK.B
Berkshire Hathaway
Greg Abel's first quarter. $390B+ cash & T-bills, 42 public equity positions (Apple/AmEx/BAC/KO/CVX dominate), operating empire of GEICO + BNSF + BHE + manufacturing/service/retail. Bear/Base/Bull presets, float credit, deferred-tax recognition slider.
NYSE: MKL
Markel Group ("Baby Berkshire")
Tom Gayner's "Baby Berkshire." Insurance underwriting (93% combined ratio Q1'26) + $11.9B 13F portfolio (post-massive Q1 trim of BRK / GOOG / HD / BN) + Markel Ventures (Industrial / Financial / Consumer). Bear/Base/Bull presets.
TSX: FFH / OTC: FRFHF
Fairfax Financial Holdings ("Canadian Berkshire")
Prem Watsa's holdco — insurance underwriting at 94% CR, $40B+ investment portfolio, but only ~$2B is US-listed (13F). Most value sits in non-US holdings (Eurobank, Fairfax India, Recipe, Quess, Atlas/Poseidon) modeled as a separate associates block. Book value $1,250/share.
Coming soon
NASDAQ: IAC
IAC Inc. (Barry Diller)
Holds ~14% of MGM Resorts (public), all of Dotdash Meredith (publishing — People, Better Homes, InStyle), Care.com, Turo stake, Vimeo stake, plus net cash. Classic Diller spin-and-stack holdco with a long history of unlocking value via spin-offs (Match Group, Vimeo, Angi).
NYSE: L
Loews Corp (Tisch family)
~92% of CNA Financial (publicly listed insurer) + 100% of Boardwalk Pipelines + Loews Hotels + Altium Packaging. Trades at persistent discount to NAV — classic Tisch playbook of patient capital and aggressive buybacks below intrinsic.
NASDAQ: LSXMA / FWONA / BATRA / LLYVA
Liberty Media tracking-stock complex (John Malone)
Four tracking stocks — Liberty Sirius XM, Liberty Formula One, Atlanta Braves Holdings, Liberty Live. Inter-company loans, attribution swaps, and the constant Malone restructuring chess game make this the gold standard of "complicated" SOTP. Will publish one workbook per tracker.
AMS: EXO / OTC: EXXRF
Exor N.V. ("European Berkshire" — Agnelli family)
Controls ~24% of Ferrari (RACE), ~15% of Stellantis (STLA), 26% of CNH Industrial, 15% of Philips, 100% of Juventus, plus growing healthcare bets (Lifenet, Institut Mérieux). Holdco discount has historically ranged 25–40%.