Comparable stake leader
DISCIPLINED GROWTH INVESTORS INC /MN
SEC ownership of GEOSPACE TECHNOLOGIES CORP
Top holders, 13D/G large-stake signals, insider positions, and transaction flow tied to CIK 0001001115.
Disclosed value leader
DISCIPLINED GROWTH INVESTORS INC /MN
Comparable rows
50/50
Latest evidence
31 Mar 2026
- Public ticker
- GEOS on Nasdaq
- Parsed ownership sources
- 13F, 13D/G, and 3/4/5
- Largest SEC-reported holder
- DISCIPLINED GROWTH INVESTORS INC /MN
- Latest 13D/G holder
- DISCIPLINED GROWTH INVESTORS INC /MN
- Latest parsed ownership date
- 31 Mar 2026
- Issuer CIK
- 0001001115
- Issuer location
- Houston, TX
Ownership snapshot
CIK-linked ownership evidence from parsed SEC filings.
2 signals
Issuer
Names, identifiers, and filing context for this profile.
2 identity fields
Ownership snapshot
Top shareholders of GEOSPACE TECHNOLOGIES CORP (13F + 13D/G + 3/4/5)
Grouped by holder across the latest SEC ownership disclosures. Start with comparable ownership when available, then verify the linked 13F, 13D/G, or 3/4/5 evidence.
Comparable stake leader
DISCIPLINED GROWTH INVEST...
Disclosed value leader
DISCIPLINED GROWTH INVEST...
Comparable rows
50/50
Latest evidence
31 Mar 2026
13F
13D/G
3/4/5
Lead comparable stake: 8.5%
13D/G row: DISCIPLINED GROWTH INVESTORS INC /MN
Showing 1-8 of 50 holder rows.
Quick read
DISCIPLINED GROWTH INVESTORS INC /MN leads the comparable SEC ownership view at 8.5%.
50 of 50 rows have a safely comparable ownership percentage. Use this as a filing-backed starting point, then open the detailed table for source links, reporting role, position value, share count, and filing date.
Open SEC evidence
Opens DISCIPLINED GROWTH INVESTORS INC /MN's linked filing trail.
Comparable ownership
Top 5
DISCIPLINED GROWTH INVESTORS INC /MN
8.5%
Tieton Capital Management, LLC
6.9%
VANGUARD CAPITAL MANAGEMENT LLC
5.1%
DIMENSIONAL FUND ADVISORS LP
4.9%
BlackRock, Inc.
2.7%
Ownership % is shown only when SEC disclosures are safely comparable across share classes.
Detailed SEC evidence table Showing 1-8 of 50 holder rows
| Holder | Evidence | Ownership % | Position | 12M Net Δ | As of |
|---|---|---|---|---|---|
| DISCIPLINED GROWTH INVESTORS INC /MN |
13F
13D/G
Company
|
8.5%
from 13D/G
|
$13,437,397
1,101,426 shares
|
— | 31 Mar 2026 |
| Tieton Capital Management, LLC |
13F
13D/G
Company
|
6.9%
from 13D/G
|
$11,128,000
912,118 shares
|
— | 31 Mar 2026 |
| VANGUARD CAPITAL MANAGEMENT LLC |
13D/G
13F
Vanguard Capital Management · Company
|
5.1%
|
$8,029,101
658,123 shares
|
$0 | 31 Mar 2026 |
| DIMENSIONAL FUND ADVISORS LP |
13D/G
13F
Company
|
4.9%
|
$10,412,654
628,404 shares
|
-$356,736 | 30 Sep 2025 |
| BlackRock, Inc. |
13D/G
13F
Company
|
2.7%
|
$4,871,245
341,602 shares
|
$0 | 30 Jun 2025 |
| Walter R. Wheeler |
3/4/5
Director
|
1.3%
|
$3,914,856
172,006 shares
|
— | 09 Feb 2026 |
| Thomas L. Davis |
3/4/5
Director
|
0.51%
|
$1,489,733
65,454 shares
|
— | 09 Feb 2026 |
| Robert L. Curda |
3/4/5
Vice President & CFO
|
0.47%
|
$1,588,300
61,112 shares
|
— | 05 Dec 2025 |
How to read this table
Rows are grouped by holder and ranked first by SEC-reported ownership % when it is safely comparable, then by disclosed holdings value. — indicates unavailable or non-comparable values; "mixed-class rows" means the latest filing spans non-comparable classes.
Forms 3/4/5 flow
Insider trading overview
Insider buy and sell flow is broadly balanced over the last 12 months. No Buy or Sell transactions have been reported since 12 Jun 2025.
Buys
$0
Insiders: 0
Sells
$0
Insiders: 0
Net
$0
Shares: 0
Window
Last 12 months
4 rolling buckets
Buy value
Sell value
Shares: 0
Shares: 0
| Window (months) | Buy shares | Sell shares | Buy value | Sell value | Net value |
|---|---|---|---|---|---|
| 0-3 | 0 | 0 | $0 | $0 | $0 |
| 3-6 | 0 | 0 | $0 | $0 | $0 |
| 6-9 | 0 | 0 | $0 | $0 | $0 |
| 9-12 | 0 | 0 | $0 | $0 | $0 |
Reporting owners
Insider holders from Forms 3/4/5
Showing 1-14 of 14 reporting-owner rows connected to GEOSPACE TECHNOLOGIES CORP. Open a relationship link for the CIK-to-CIK filing trail.
Rows
14
Largest Forms 3/4/5 holder
Walter R. Wheeler
Net 12M change
$0
Latest report
09 Feb 2026
| Name | Relationship | Holdings Value | Past Year Net Change | Change % | Valuation | Report Date |
|---|---|---|---|---|---|---|
| Walter R. Wheeler | Director | $3,914,856 | Mixed | 09 Feb 2026 | ||
| Gary D. Owens | Director | $3,245,693 | Mixed | 07 Feb 2024 | ||
| Robert L. Curda | Vice President & CFO | $1,588,300 | Mixed | 05 Dec 2025 | ||
| Thomas L. Davis | Director | $1,489,733 | Mixed | 09 Feb 2026 | ||
| Richard F. Miles | Director | $1,140,276 | Mixed | 09 Feb 2026 | ||
| Richard James Kelley | President & CEO | $1,090,982 | Mixed | 05 Dec 2025 | ||
| Edgar R. Giesinger Jr. | Director | $978,680 | Mixed | 09 Feb 2026 | ||
| Robbin B. Adams | SVP & Chief Technical Officer | $902,049 | Mixed | 21 Nov 2024 | ||
| Margaret Ashworth | Director | $782,944 | Mixed | 09 Feb 2026 | ||
| Michael J. Sheen | SVP & Chief Technical Officer | $472,346 | Mixed | 21 Nov 2022 | ||
| Stephen C. Jumper | Director | $339,124 | Mixed | 09 Feb 2026 | ||
| Ronald T. Bushey | Chief Technical Officer | $315,180 | Mixed | 05 Dec 2025 | ||
| Tina M. Langtry | Director | $175,863 | Mixed | 09 Feb 2023 | ||
| Kenneth Asbury | Director | $74,415 | Mixed | 02 Feb 2022 |
Recent insider transactions for GEOSPACE TECHNOLOGIES CORP
Showing up to 300 recent insider transactions from the last 12 months.
| Insider | Symbol | Class | Transaction | % | SEC-reported value | SEC-reported price | Shares | Shares owned | Date | Ownership |
|---|---|---|---|---|---|---|---|---|---|---|
| Richard F. Miles | GEOS | Common Stock | Award | 7.85% | 3,500 | 48,100 | 09 Feb 2026 | Direct | ||
| Thomas L. Davis | GEOS | Common Stock | Award | 5.65% | 3,500 | 65,454 | 09 Feb 2026 | Direct | ||
| Edgar R. Giesinger Jr. | GEOS | Common Stock | Award | 8.86% | 3,500 | 43,000 | 09 Feb 2026 | Direct | ||
| Richard James Kelley | GEOS | Common Stock | Tax liability | -0.65% | -275 | 41,977 | 05 Dec 2025 | Direct | ||
| Robert L. Curda | GEOS | Common Stock | Tax liability | -0.27% | -165 | 61,112 | 05 Dec 2025 | Direct | ||
| Ronald T. Bushey | GEOS | Common Stock | Tax liability | -2.22% | -275 | 12,127 | 02 Dec 2025 | Direct | ||
| Ronald Todd Bushey | GEOS | Comm | Award | 47.6% | 4,000 | 12,402 | 25 Nov 2025 | Direct | ||
| Robert L. Curda | GEOS | Common Stock | Award | 6.98% | 4,000 | 61,277 | 25 Nov 2025 | Direct | ||
| Richard James Kelley | GEOS | Common Stock | Award | 23.4% | 8,000 | 42,252 | 25 Nov 2025 | Direct | ||
| Ronald Todd Bushey | GEOS | Common Stock | Tax liability | -2.3% | -198 | 8,402 | 20 Nov 2025 | Direct | ||
| Ronald Todd Bushey | GEOS | Common Stock | Award | 72% | 3,600 | 8,600 | 20 Nov 2025 | Direct | ||
| Richard James Kelley | GEOS | Common Stock | Tax liability | -0.86% | -298 | 34,252 | 20 Nov 2025 | Direct | ||
| Richard James Kelley | GEOS | Common Stock | Award | 15% | 4,500 | 34,500 | 20 Nov 2025 | Direct | ||
| Robert L. Curda | GEOS | Common Stock | Tax liability | -0.34% | -198 | 57,277 | 20 Nov 2025 | Direct | ||
| Robert L. Curda | GEOS | Common Stock | Award | 6.68% | 3,600 | 57,475 | 20 Nov 2025 | Direct |
* marks a reported price that did not pass the local price check.