| Period | Weighting | Quarter | ||||||
|---|---|---|---|---|---|---|---|---|
| Company | Longest | Shortest | Min. | Avg. | Max. | First | Latest | ↓ Count |
| SIMPLEX TRADING, LLC | 18 | 2 | 0.00% | 0.00% | 0.01% | Q1 2015 | Q2 2024 | 26 |
| CONCOURSE FINANCIAL GROUP SECURITIES, INC. | 24 | 24 | 0.00% | 0.00% | 0.00% | Q3 2018 | Q2 2024 | 24 |
| GROUP ONE TRADING LLC | 17 | 17 | 0.00% | 0.01% | 0.10% | Q1 2020 | Q1 2024 | 17 |
| Citadel Advisors | 4 | 4 | 0.00% | 0.00% | 0.00% | Q4 2014 | Q3 2015 | 4 |
| JANE STREET GROUP, LLC | 3 | 3 | 0.00% | 0.00% | 0.00% | Q2 2022 | Q4 2022 | 3 |
| JPMORGAN CHASE & CO | 1 | 1 | 0.00% | 0.00% | 0.00% | Q3 2021 | Q3 2021 | 1 |
This page lists all the filers that currently own ALPHA PRO TECH LTD or have owned ALPHA PRO TECH LTD in the past.