Madrone Advisors, LLC — 13F Holdings & Portfolio

CIK 1964563 · latest 13F-HR filed 2026-08-13

Madrone Advisors, LLC manages $1.39B in 13F-reported U.S. long-equity assets across 6 reported positions as of its 2026-06-30 13F-HR filing. Its largest disclosed positions are STUB (69.92%), STNE (19.69%), QXO (5.22%). Quarter over quarter (versus its 2026-03-31 filing) the fund opened 1 new position and exited 0; 1 existing position rose in reported value and 4 fell.

AUM is the long-equity portion reported on Form 13F-HR. Excludes short positions, cash, foreign holdings, and non-13F assets. For informational purposes only — not investment advice.

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AUM
$1.39B

Long-equity book

Holdings
6

Distinct positions

Period
2026-06-30

Filed 2026-08-13

Q/Q Activity
+1 / −0 / ↑1 / ↓4

vs 2026-03-31

Portfolio charts

Latest quarter's book, what changed, and how the portfolio has evolved across filings.

Portfolio map

Q2 26

Box size = position value; colour = change in share count vs the prior quarter (green added, red trimmed, blue new). Rows split across managers or share classes are combined. Click a box for the stock.

Sector mix

% of 13F value

Sectors from each company's SIC code; funds and ETFs grouped separately.

Biggest buys and sells

Q1 26 → Q2 26

Estimated from the change in shares held × the quarter-end price, so price moves alone don't count as buying. New and exited positions are included.

13F assets and positions

4 quarters

Total reported 13F value (bars) and number of positions (line) each quarter. Value changes include market moves.

Top positions over time

reported value

The eight largest current positions, valued at each quarter end.

Concentration

top 10 = 100%

Cumulative share of the portfolio held in the largest N positions.

Firm Profile & Key People

As of the firm’s regulatory filing dated Mar 24, 2026.

Assets Under Management
$254.3M
Discretionary
$10.9M
Employees
1
Accounts
375
Name Title / Status Ownership Type
ZAIDLIN, MIKE, HARRY ControlMANAGING MEMBER/CCO
since May 2009
75% or moreIndividual

Quarter-over-quarter changes

Changes in reported position value vs the prior 13F, so price moves count too, not just shares bought or sold.

Top Adds (vs prior quarter)

Show all 1 →

Top Trims

Show all 4 →

Exited Positions

  • No exits this quarter.
Show all 0 →

Madrone Advisors, LLC Holdings (2026-06-30)

Rows tagged Call or Put are options positions, not stock. Per SEC Form 13F-HR, Value shows the notional value of the underlying (shares covered × underlying price), not the option premium. Shares is the number of underlying shares covered (divide by 100 for contract count).

# Issuer Symbol CUSIP Value Weight Shares Type
1 STUBHUB HLDGS INC STUB 86384P109 $975.3M 69.92% 75,780,055 SH
2 STONECO LTD STNE G85158106 $274.7M 19.69% 25,339,276 SH
3 QXO INC QXO 82846H405 $72.8M 5.22% 4,215,198 SH
4 VANGUARD INTL EQUITY INDEX F VT 922042742 $40.3M 2.89% 256,758 SH
5 CAPITAL ONE FINL CORP COF 14040H105 $22.0M 1.58% 109,506 SH
6 FIGMA INC FIG 316841105 $9.7M 0.70% 538,956 SH
Filing History
Period Filed AUM Holdings Accession
2026-06-30 2026-08-13 $1.39B 6 0001964563-26-000009
2026-03-31 2026-05-14 $1.03B 5 0001964563-26-000006
2025-12-31 2026-02-13 $1.62B 5 0001964563-26-000003
2025-09-30 2025-11-14 $2.03B 6 0001964563-25-000008
Filer Information
Address
PO BOX #6476
DENVER, CO 80206
Phone
(650) 854-8304
Filing Manager
MADRONE ADVISORS, LLC
Denver, CO
Signatory
Erron Smith
Assistant Secretary