Company · Ownership research

TENARIS SA TS

CIK 0001190723 · CUSIP 88031M109

Insider tradingInitial holdingsInstitutional holders

Quarter-end disclosures, not live holdings.

Several CUSIPs are reported for this company; this page shows CUSIP 88031M109 (TS), not CUSIP 88031M909 (TS), CUSIP 88031M959 (TS), CUSIP L90272136 (TNRSF), and does not merge CUSIPs.

This page lists the top 20 of 225 rows by value; the complete set is available through the API.

Some filings reported values in thousands; those figures were scaled ×1,000 to dollars.

Top 20 institutions

Weight means this stock's share of the manager's own portfolio.

By reported value

#	Manager	Value	Manager weight	Change vs prior	Source
01	Westwood Global Investments, LLC CIK 1356513 · Amended · View history	$271.55M 7,591,660 shares	13.56%	-239.71K(-3.10%)Reduced	SEC filing ↗ Nov 13, 2025	▾
02	RENAISSANCE TECHNOLOGIES LLC CIK 1037389 · View history	$119.85M 3,350,644 shares	0.16%	+459.10K(+15.90%)Added	SEC filing ↗ Nov 13, 2025	▾
03	FMR LLC CIK 315066 · View history	$82.10M 2,295,249 shares	0.00%	-3.22K(-0.10%)Reduced	SEC filing ↗ Nov 13, 2025	▾
04	WELLINGTON MANAGEMENT GROUP LLP CIK 902219 · View history	$76.40M 2,135,993 shares	0.01%	+36.72K(+1.70%)Added	SEC filing ↗ Nov 14, 2025	▾
05	PRICE T ROWE ASSOCIATES INC /MD/ CIK 80255 · View history	$63.94M 1,787,345 shares	0.01%	+89.35K(+5.30%)Added	SEC filing ↗ Nov 14, 2025	▾
06	VAN ECK ASSOCIATES CORP CIK 869178 · View history	$57.61M 1,610,593 shares	0.05%	-5.10K(-0.30%)Reduced	SEC filing ↗ Nov 13, 2025	▾
07	Encompass Capital Advisors LLC CIK 1541901 · View history	$51.25M 1,432,704 shares	2.31%	-300.08K(-17.30%)Reduced	SEC filing ↗ Nov 14, 2025	▾
08	MORGAN STANLEY CIK 895421 · Amended · View history	$41.91M 1,171,617 shares	0.00%	+52.86K(+4.70%)Added	SEC filing ↗ May 27, 2026	▾
09	DIMENSIONAL FUND ADVISORS LP CIK 354204 · View history	$40.57M 1,134,260 shares	0.01%	+192.79K(+20.50%)Added	SEC filing ↗ Nov 12, 2025	▾
10	Optiver Holding B.V. CIK 1859606 · View history	$32.38M 905,328 shares	0.53%	+589.63K(+186.80%)Added	SEC filing ↗ Nov 10, 2025	▾
11	ABC ARBITRAGE SA CIK 2049221 · View history	$27.73M 775,204 shares	2.73%	+307.94K(+65.90%)Added	SEC filing ↗ Nov 6, 2025	▾
12	GOLDMAN SACHS GROUP INC CIK 886982 · View history	$25.22M 705,183 shares	0.00%	-225.05K(-24.20%)Reduced	SEC filing ↗ Nov 14, 2025	▾
13	BlackRock, Inc. CIK 2012383 · View history	$22.93M 641,138 shares	0.00%	+14.04K(+2.20%)Added	SEC filing ↗ Nov 12, 2025	▾
14	MASSACHUSETTS FINANCIAL SERVICES CO /MA/ CIK 912938 · View history	$21.57M 602,886 shares	0.01%	-134.87K(-18.30%)Reduced	SEC filing ↗ Oct 29, 2025	▾
15	D. E. Shaw & Co., Inc. CIK 1009207 · View history	$21.36M 597,082 shares	0.02%	+375.07K(+168.90%)Added	SEC filing ↗ Nov 14, 2025	▾
16	MILLENNIUM MANAGEMENT LLC CIK 1273087 · View history	$20.55M 574,423 shares	0.02%	-202.54K(-26.10%)Reduced	SEC filing ↗ Nov 14, 2025	▾
17	Medina Value Partners, LLC CIK 1843543 · View history	$20.07M 560,954 shares	4.69%	+4.90K(+0.90%)Added	SEC filing ↗ Nov 13, 2025	▾
18	ASSETMARK, INC CIK 1344551 · View history	$17.18M 480,215 shares	0.04%	+10.99K(+2.30%)Added	SEC filing ↗ Nov 6, 2025	▾
19	Harding Loevner LP CIK 928196 · View history	$14.60M 408,147 shares	0.11%	-42.45K(-9.40%)Reduced	SEC filing ↗ Nov 14, 2025	▾
20	JANE STREET GROUP, LLC CIK 1595888 · View history	$13.53M 378,260 shares	0.02%	+83.00K(+28.10%)Added	SEC filing ↗ Nov 14, 2025	▾

Showing 20 / 225 institutions. The complete set is available through the API.

Coverage & totals by quarter

Reporting institutions

225

Cancelled or null records excluded

Disclosed shares

35,694,546

Not deduplicated across managers

Disclosed value

$1.28B

Not market cap or free float

Reporting institutions by quarter

Counts also change with data coverage and reporting entities; they do not measure net buying. Distinct managers with a live stock row in this CUSIP; totals may include overlapping filings and are not a share of the company.

TENARIS SA · Q3 2025

Explore all 225 reporting institutions.

This page includes 20 of 225 reporting institutions. Log in to look up the full history beyond 3 years, use advanced screening & filtering, download CSV, and get the complete set through the Akkru API.

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Sources, coverage & how to read this data

Figures are as reported to the SEC and merged with later amendments where Akkru could match them. Preview limits apply to what is listed, not to the totals, which come from the complete reported data. Nothing is zero-filled: a missing quarter or month is shown as missing.